Let's talk about bio load.

[Aquattro]

So looking at skimmers, most are rated for different volumes at different bioloads.
How do we measure that? I mean, quantitatively, what's a medium bio load? Or heavy? Or medium light?
Compared to what?

How do you gauge your bioload?

[Proteus]

Good question. I think I have a heavy bit load with 7 fish in my tank but there all small basslets and two fire fish. So is that low compared to wrasses or tangs

[Aquattro]

No idea. And that's weird, cause I usually have an answer, even if I make it up :)

This time I got nuthin' lol

I think I have a medium(ish) load. On the light side, but I feed heavy. Sort that one out!

[Proteus]

Maybe bit load should be based on amount of food you use.

[Aquattro]

Maybe bit load should be based on amount of food you use.

Do we weight it per gallon?

I have a 6" angel, a 4" tang, 8 Bartlett's Anthias (2"), a Leopard wrasse about 4 inches, 2 clowns and another anthias (Lyretail). 50 frags. 3 LPS various sizes. 40 snails. 2 abalone. Some sand snails.

107g of water, 50 pounds of rock. Give or take.

We call this medium? Heavy? Light? I dunno. I picked medium because it's in the middle :)

[Proteus]

Do we weight it per gallon?

I have a 6" angel, a 4" tang, 8 Bartlett's Anthias (2"), a Leopard wrasse about 4 inches, 2 clowns and another anthias (Lyretail). 50 frags. 3 LPS various sizes. 40 snails. 2 abalone. Some sand snails.

107g of water, 50 pounds of rock. Give or take.

We call this medium? Heavy? Light? I dunno. I picked medium because it's in the middle :)

I guess a pound of food is a pound of poop regardless of how many fish

[Aquattro]

I guess a pound of food is a pound of poop regardless of how many fish

No, would depend on age of fish (is fish growing still?), temp of water (effect on metabolism, etc). A pound in is not a pound out. And sand beds complicate the equation. What gets retained in the sand vs bare bottom. What gets removed as solids in a filter sock if you use one?

This is complicated :)

[Proteus]

I guess you would have to find a way to calculate the time it takes your tank to process a days waste. Having a number value to the amount of organics in the water column. You could turn a day into sections. 4 hours to process the waste is low 8 hour medium and so on.



But I'm not tgat kind of smart

[The Guy]

Pretty confusing subject! I kinda thought bio load depends on how many fish you have. Sea_Horse Fanatic or Anthony as some of us know him has a 160 g DT and lots of fish and I know he considers it heavy bio load, hopefully he'll see this thread and chime in and shed some light for us. :confused:

[christyf5]

I consider my bioload medium and the skimmer I have is "realistically rated (TM)" for 250gal or 180gal heavy bioload. It seems to do ok and I've never not had algae (except for that one time) so it does as well as I expect it to.

I generally gauge my bioload on fish type and size. Tangs eat a lot and crap a lot and I have a "enough" of them so I'd consider myself medium bioload leaning towards heavy-ish.

Interesting question. I also am interested in how people relate their bioload to skimmer size and "over skimming". Is this even possible?

[mrhasan]

My theory (as if anyone cares):

Testing of bio-load has to be through titration but instead of adding drops of some chemical, you have to keep on adding fishes till you see (whichever comes first):

1. Sudden growth of algae
2. Sudden deterioration of water quality
3. Do water change more than you would like to

When any of the three results matches, you have a heavy bio-load. Small bioload is the point where you don't see any fish in the tank (or you are an irrational environmental activist) and medium would be anything between small+1 and heavy-1.

[straightrazorguy]

I don't think you will see a sudden anything. I think of it as more gradual thing. It is a biological system, and, depending on your rock, sand, reactors, etc you may or may not be able to process a certain amount of fish waste. The bacteria will adapt and multiply to the point where they encounter a limitation of some sort (usually carbon). If you supply that, they will continue to grow to match the bio-load.

I also think of corals as consumers of nutrients, rather than adding to the bio-load. Am I wrong?

[reefwars]

While they use nutrients they do not really remove them from a system just process them and get rid of what's not used, this may be food for other life including other coral . Certain things can not get processed out and eventually need some sort of export out of the system.

As for the size thing , its not always the biggest animals with largest bioload , snails , urchins and sea hares tend to do a lot of pooping lol

I would bet a sea hares waste is ten times as much as fish three times it's size.

[Aquattro]

So then, how do I estimate my bioload? Good question, huh?? :)

[reefwars]

I always just get a skimmer twice rated my volume size , seems to work well lol

[tom55228]

i have always gauged my bio load on type of fish and how many I have and size and feeding .I have a 90 gal tank and I think I am pushing the heavy side of bioload I don't think theres away to measure other then maybe skimate from your skimmer .I like the idea of a skimmer twice the size or close to more then half of water volume . just my two cents worth

[sphelps]

So then, how do I estimate my bioload? Good question, huh?? :)

Use a calculator..

http://aqadvisor.com/AqAdvisorMarine.php

[Aquattro]

Use a calculator..

http://aqadvisor.com/AqAdvisorMarine.php

Almost had it there :) Most fish missing from list.

[Aquattro]

I always just get a skimmer twice rated my volume size , seems to work well lol

Ya, works well. Guess there's no real answer to this :)

[Proteus]

Way more complicated than I would have ever thought. After doing some reading the bioload also is affected buy amount of available oxygen, surface area (which is probably for oxygen) free swimming area and fish behaviour (sand sifters , schooling)

[mrhasan]

Ya, works well. Guess there's no real answer to this :)

I thought you dont care about these sorts of things in the hobby. You are my idol for the LTFA method (and I am not kidding).

[reefwars]

Not to mention bacteria of all sorts , these are a bio load often overlooked;)

[Aquattro]

I thought you dont care about these sorts of things in the hobby. You are my idol for the LTFA method (and I am not kidding).

lol! You're right, I don't really care, just thought it would be an interesting discussion. I'm looking at all kinds of skimmers that give different ratings based on bioload, and it occurred to me that there really is no measurable way to gauge this. Based on the thousands of responses, it's a tough question, or not many people are as curious as I :)

For me, get big skimmer, make big foam, remove big poop. Done job.

[mike31154]

I read somewhere that skimmers, no matter how efficient will never completely remove all organics, there's a very small difference between the best & mediocre ones in that regard. I doubt that there'a 'formula' to measure bioload that will work consistently for any given person's tank. If a tank is overstocked & under maintained with respect to water changes, I doubt that even the best skimmer will keep up.

One would think that measuring nitrates & phosphates would provide some indication of whether one's bioload is exceeding maintenance or skimming performance. Or if one is battling algae issues. I'm stumped because if anything my bioload has decreased lately, hair algae issues I've had in the past are almost non existent at the moment, but I recently tested my water (after not having done so for many moons) and my nitrate reading was about the highest I can remember.... yet minimum algae issues & the critters including anemone & coral I have are doing well....

[StirCrazy]

I think the best way is by food usage, more food the heavier the bioload, but this is complicated by natural occurring food in the tank, like algae that your tangs might eat and so on.

In the end though the only way to tell if your skimmer is big enough is to see if it is removing what it is supposed to by water quality tests. That's why traditionally we have always doubled the size of skimmer that we thought we needed.

Steve

[Proteus]

The problem with doubling up your skimmer size is the removal of beneficial organism. This has been shown in tanks that use zeo or like methods.

[reefwars]

The problem with doubling up your skimmer size is the removal of beneficial organism. This has been shown in tanks that use zeo or like methods.

what organisms are we removing exactly compared to their reproduction rate? are we talking bacteria?

ratings on skimmers vary so do we go by pump specs or by manufacture recommendations, and whats considered a healthy population to begin with and does age of tank play a factor?

im sure skimming removes lots of things including some beneficial bacteria , metals , phosphates and organics etc. alot of these id rather pull out then save , the amount of beneficial bacteria ratio to the reproduction rates it would take a long time to see an effect or complete wipe out, things added to the tank are going to replenish some of these organisms over time as well as the food sources and carbon we add, and new bacterias are always willing to take the role of old ones.

so overall ive always doubled my skimmer , i also carbon dose and rely on my skimmers performance to make it as effcient as it can be since i dont run filter socks or any other way of removing it.

ive often tied new systems into mine so its nice to have a skimmer that can handle a larger water volume and ive also been known to upgrade.
over the years ive had more issues of skimmers not performing rather then performing to well :)

[Proteus]

I do agree with you. Just stating based on threads on zeovit forum. It's always been suggested to turn off skimmer while dosing and for few hours after. Also zeo claims that using needle wheel skimmer are to efficient. Pulling out the dosed bacteria. I do run a skimmer that's more than 2x the capacity of my tank, but only run it 16 hours a day.

[reefwars]

yes there is , and which is one of the reasons i always dose down stream from the skimmer.

[Dearth]

Another consideration is when setting up a new tank it skims a ton and as the tank matures the amount that is skimmed becomes less and less and that tends to throw a lot of reefers for a loop this can also be said for putting a new skimmer in an established tank

But in the grand scheme of things I honestly don't think there is an accurate way to measure bio load it just comes down to user preference and past experience IMO

[sphelps]

Over-skimming has nothing to do with removing beneficial bacteria, while such bacteria exists in the water column the amount of it compared to what attaches to surfaces in basically zero. Skimming removes bacteria about as effectively as water changes. Over skimming removes desirable elements such as potassium which can effect coral health. This can be avoided even with grossly over-sized skimmers by dry skimming rather than wet skimming and dosing to compensate.

In terms of zeovit the system is based on strong skimming, I remember previous versions of the guide actually stated you couldn't use a skimmer that was too large however that probably resulting in some using ridiculously over-sized skimmers meaning elements where depleted faster than they could be added. Thus the added note stating not too use a skimmer "too oversized" but you should still use an "over-sized skimmer". Also nothing official from zeovit suggests shutting a skimmer off during dosing, only to dose downstream of the skimmer in order to give the bacteria a chance to populate within the aquarium (same for the reactor mull).

As mentioned earlier, the basis of this method relies on export of harmful substances through skimming. Continuous use and frequent cleaning should be conducted in order to keep the skimmer performing at its maximum level. The results are better when the skimmer is adjusted in order not to produce too much concentrated skimmate (wet skimming). We would like to point out that it is our thought that needle wheels may precipitate certain elements and destroy plankton. These elements, e.g. such as potassium, will need to be re-added to the system. Do not use a skimmer that is too oversized or employ wet skimming if you use a needle wheel skimmer. We recommend the use of venturi type skimmers.

[SoloSK71]

So then, how do I estimate my bioload? Good question, huh?? :)

Dissolved oxygen, actual vs. ideal/theoretical

Charles

[Aquattro]

Dissolved oxygen, actual vs. ideal/theoretical

Charles

Near impossible for a hobbyist to measure, but that might do it. Perhaps redox values instead?

[Proteus]

I've though about monitoring orp but after all the research I've done its about as important as ph

[mikellini]

Over-skimming has nothing to do with removing beneficial bacteria, while such bacteria exists in the water column the amount of it compared to what attaches to surfaces in basically zero. Skimming removes bacteria about as effectively as water changes.

This isn't exactly true... For example, systems in which organic carbon is dosed remove a lot of bacteria via foam fractionation (skimming). This is actually the primary way in which such systems control phosphates; by removing the bacteria that bind/use/consume them from the aquarium. Also why skimmate colour changes significantly when dosing carbon (ethanol, vinegar etc). Zeovit systems also remove a substantial amount of bacteria by skimming; when the 'mulm' (basically bacterial biomass) is shaken and released, whatever isn't immediately eaten or otherwise used by the inhabitants is skimmed out.

[Samw]

Near impossible for a hobbyist to measure, but that might do it. Perhaps redox values instead?

Why is dissolved oxygen impossible to measure? There are dissolved oxygen meters. I have one.

[Aquattro]

Why is dissolved oxygen impossible to measure? There are dissolved oxygen meters. I have one.

Meters are rare items owned by hobbyists. And titration kits don't work well at all.
Not impossible, but not something that is useful, therefore difficult to justify a meter.
Hobbyist meters are also likely not maintained well, so the value could be way off.

[Samw]

Meters are rare items owned by hobbyists. And titration kits don't work well at all.
Not impossible, but not something that is useful, therefore difficult to justify a meter.
Hobbyist meters are also likely not maintained well, so the value could be way off.

It was useful for me to determine that my tank was overstocked with low DO at night. Without heavy aeration turned on at night, my DO levels were lethal to oxygen demanding fish whereas another reefer who borrowed my meter had a lightly stocked reef where the DO hardly dropped at night. Even with aeration at night my DO was low due to the high bioload.

Here's an affordable one
http://www.amazon.com/Milwaukee-Economy-Portable-Dissolved-Calibration/dp/B007Z4KKIQ/ref=pd_sim_sbs_indust_1?ie=UTF8&refRID=0Q2B09JCANWD2MRRMSER

[Aquattro]

Here's an affordable one


Still $150 bucks! I know so many people that won't splurge on a new refractometer for $40 :) And that's bit more useful :)

[reefwars]

Some reading for anyone who's interest in bacteria numbers , removal and what carbon dosing does to certain bacteria.

http://www.advancedaquarist.com/2011/3/aafeature

[sphelps]

This isn't exactly true... For example, systems in which organic carbon is dosed remove a lot of bacteria via foam fractionation (skimming). This is actually the primary way in which such systems control phosphates; by removing the bacteria that bind/use/consume them from the aquarium. Also why skimmate colour changes significantly when dosing carbon (ethanol, vinegar etc). Zeovit systems also remove a substantial amount of bacteria by skimming; when the 'mulm' (basically bacterial biomass) is shaken and released, whatever isn't immediately eaten or otherwise used by the inhabitants is skimmed out.

Yes and what exactly does that have to do with over skimming? We're talking about two different things.

[Proteus]

Thanks Denny that's a long read but very good

[mikellini]

Yes and what exactly does that have to do with over skimming? We're talking about two different things.

You said that skimming removes about as much bacteria as a water change, which really isn't the case. It sounded like you didn't understand how skimming worked.

[mrhasan]

:pop2:

[sphelps]

You said that skimming removes about as much bacteria as a water change, which really isn't the case. It sounded like you didn't understand how skimming worked.

A skimmer can only remove bacteria from the water column, same as just removing the water. Bacteria adheres to surfaces significantly more than the water itself thus removing the water or skimming heavier will not diminish a bacteria population period. This applies to carbon dosing or zeo, over skimming has no negative effects on a bacteria population, even if you're dosing it provided you dose downstream. So my point was when over sizing a skimmer to your bio-load the risk relates to removing excess essential elements such as potassium not bacteria. Make sense yet?

[mikellini]

A skimmer can only remove bacteria from the water column, same as just removing the water. Bacteria adheres to surfaces significantly more than the water itself thus removing the water or skimming heavier will not diminish a bacteria population period. This applies to carbon dosing or zeo, over skimming has no negative effects on a bacteria population, even if you're dosing it provided you dose downstream. So my point was when over sizing a skimmer to your bio-load the risk relates to removing excess essential elements such as potassium not bacteria. Make sense yet?

I understood your central point from the start, however saying a skimmer removes as much bacteria as a water change was mixed in there. Fact is, you can't compare the two. And truthfully a skimmer can remove a lot of bacteria.

[Samw]

Still $150 bucks! I know so many people that won't splurge on a new refractometer for $40 :) And that's bit more useful :)

Ok, but if you had one, it can help you determine whether your bioload is too high. :)

[Aquattro]

Ok, but if you had one, it can help you determine whether your bioload is too high. :)

Ok, I'll give you that :)

However, that doesn't really address the question.

Skimmer x is good for 200g @ light load, 150g @ med load, 100g high load. How does one determine if skimmer x is appropriate for their 120g tank?

Personally, I've been doing this a couple years now, I just know. I know my bio load, pretty comfortable guessing bio load capacity, and I'm confident in my abilities to size a skimmer.
But for most consumers new to the hobby, what does that mean? Does skimmer x meet my needs? Or do I need x +/-1 for my tank? Generally bigger is better, but if I go too large, I may not have enough load to get proper foam development.

All theoretical discussion with no real answer, just something to kick around.

[Proteus]

Generally bigger is better, but if I go too large, I may not have enough load to get proper foam development.

Absolutely, found this out buy only running skimmer part time. My skimmer is rate more than double my tank volume and while running 24/7 I only ever got murky water and found it hard to tune the skimmer. Now running at night my skimmate has become very dry and sludgy.
This may put me at a light bioload for skimmer but fully stocked for tank size

[sphelps]

I understood your central point from the start, however saying a skimmer removes as much bacteria as a water change was mixed in there. Fact is, you can't compare the two. And truthfully a skimmer can remove a lot of bacteria.

Disagree, if for some reason I wanted to remove bacteria from the water column I could change 100% of the water which would be far more effective than what a skimmer could do. Ultimately changing a given amount of water on a certain frequency would compare directly to what a skimmer would accomplish, same as removing any organics. But that's all pointless information irrelevant to anything we're talking about here, the comparison was only made based on the common misconception large water changes are harmful because they remove beneficial bacteria, so I was making the same comment relating to large skimmers...

[mikellini]

Disagree, if for some reason I wanted to remove bacteria from the water column I could change 100% of the water which would be far more effective than what a skimmer could do. Ultimately changing a given amount of water on a certain frequency would compare directly to what a skimmer would accomplish, same as removing any organics. But that's all pointless information irrelevant to anything we're talking about here, the comparison was only made based on the common misconception large water changes are harmful because they remove beneficial bacteria, so I was making the same comment relating to large skimmers...

Again that's a poor example. Bacteria multiply exponentially, it's not like removing a dissolved organic. Doing a 100% water change would remove all of the bacteria in the water (once), a skimmer will remove continuously.

I agree, a bit off topic. Sorry for that

[Aquattro]

Doing a 100% water change would remove all of the bacteria in the water (once), a skimmer will remove continuously.


Here's my take on that. I don't care at all about any bacteria in water, so if it's there or not, makes no difference. The amount free in the water column is insignificant, so let the skimmer take out however much it wants.

[Wheelman76]

Here's my take on that. I don't care at all about any bacteria in water, so if it's there or not, makes no difference. The amount free in the water column is insignificant, so let the skimmer take out however much it wants.


+1

[mikellini]

Here's my take on that. I don't care at all about any bacteria in water, so if it's there or not, makes no difference. The amount free in the water column is insignificant, so let the skimmer take out however much it wants.

If you're doing zeovit or dosing carbon, there will be a significant amount of bacteria in the water column at times. Enough that you can see clumps

[SoloSK71]

Going back to your original post, I suggest that you get a skimmer that is rated for your water volume as 'heavily stocked' and leave it at that.

Charles

[Aquattro]

If you're doing zeovit or dosing carbon, there will be a significant amount of bacteria in the water column at times. Enough that you can see clumps

Nope, sorry, no clumps. And if there were clumps, that's bound and probably not really active in what I want bacteria to be doing, and therefore, again, insignificant. The only bacteria I'm concerned with are those on substrate, which are not removed in any amount, by any means, that concerns me.

[Aquattro]

Going back to your original post, I suggest that you get a skimmer that is rated for your water volume as 'heavily stocked' and leave it at that.

Charles

Yes, I think that's the real answer, just thought it would be an interesting discussion

[SoloSK71]

It has been and is. I just suffer from the guy tendency to offer solutions instead of discussing things :)

Charles

[mikellini]

Nope, sorry, no clumps. And if there were clumps, that's bound and probably not really active in what I want bacteria to be doing, and therefore, again, insignificant. The only bacteria I'm concerned with are those on substrate, which are not removed in any amount, by any means, that concerns me.

When dosing carbon (and zeo is carbon dosing as well), a biofilm of bacteria is formed. It can form on the sand, rock, zeolites, carbon/gfo, biopellets, glass - whatever. This occurs because dosing organic carbon removes a limiting factor in growth, allowing nitrogen processing bacteria to thrive. These ARE the bacteria you're concerned with. The 'clumps' or biomass bacteria occur when the biofilm becomes too thick, and excess bacteria break off (also happens when shaking zeolites and releasing 'mulm'). But this is just a visual example of what already occurs when dosing carbon; the bacterial count in the water column goes up. You actually WANT to skim/remove these because in doing so you also remove nitrogen and phosphorus from the system. So while it's true that generally you shouldn't be concerned about removing 'too much' bacteria from the water column by protein skimming, that doesn't mean it doesn't happen. It happens to a degree in every reef aquarium, and moreso in those that dose organic carbon.

BTW I do feel this is relevant to the conversation, as dosing carbon (and the resulting increase in bacteria) should actually be considered as an increase in the bioload of an aquarium IMO. That is, if you are dosing carbon, you should increase the capacity of your skimmer accordingly.

[Aquattro]

Like you said, excess bacteria. The ones I don't care about. Maybe I'm just not understanding your point, but I will agree that aggressive skimming is desirable to remove this excess.

[Proteus]

I have only seen clamping in my plumbing. But since dosing biomate it has gone. I do know of carbon dosing peeps who said the rock or sand looked dirty from the mulm build up though. But with proper husbandry it shouldn't get to that point

[mikellini]

Like you said, excess bacteria. The ones I don't care about. Maybe I'm just not understanding your point, but I will agree that aggressive skimming is desirable to remove this excess.

IMO the solution lies in DC controllable pumps. Get a skimmer that is easily oversized, and turn it down until you get a consistent foam head. Problem solved?

[Aquattro]

IMO the solution lies in DC controllable pumps. Get a skimmer that is easily oversized, and turn it down until you get a consistent foam head. Problem solved?

Really? The last thing I would ever use is a controllable pump on a skimmer. Over complicates things, adds additional cost that doesn't need to be there, and once set, you probably never have to adjust again.
An appropriately matched skimmer/pump set should already be at the right values and the only tweaking should be air volume and water height.

I know I'm old and set in my ways, but adding features for the sake of adding features is not something I buy into.

[reefwars]

Sure Says the guy who's never owned a dc skimmer lol

fwiw dc skimmers are actually cheap for what they are rated to , more so than a lot of the more common AC brand names.


Remember the article on skimmers and how much they actually removed , (less than %20 if i remember correctly ) I believe the reef octopus performed one of the worst yet still a go to skimmer for a lot reefers.So I'm not sure on how good a job our current technology actually is.

Back to the bac.....


While there are bacteria that can and can't be skimmed (see article) the ones that we want are indeed skimmed out ......those rock and surface clinging bacteria everyone speaks of.

But how are they skimmed if they only attach to rock?

[reefwars]

My only beef with dc skimmers and dc pumps all together is the crappy lifeline and cheap parts they can have.

[Aquattro]

Sure Says the guy who's never owned a dc skimmer lol



Fair enough, but I don't conceptualize the point. Seems odd to want a controllable pump that I don't want to change. Just start with the right sized pump and go.

But, I've been known to be wrong before. Not often, but it happens :razz:

I just have no interest in fiddling with things, I want to plug it in and be done with it.

[reefwars]

I do like the idea of the controllable pumps , as I found it very handy to fine tune a good head as well the slow start is a nice feature, but there are also things I don't like either ,so I didn't go dc for my new skimmer either I went the other way.

I def agree get something adequate from the start regardless of the name or style.

One feature that is a must have for me on most any skimmer is a large cup , I hate small cups:)

[riceboy]

I'm gonna get flamed for this but oh well, lol in my tank (100 gallons ish) i have naso tangs,blue tang, yellow tang, kole tang, 2 clownfish, 8 green chromis, male& female manderin goby, 3 square anthias, diamond goby, and a handful of hermit crabs and emerald crabs, so pretty heavy bioload. I still do my checks for phosphate (which is 0.02ppm according to the hana checker) and have never really checked for nitrates. I'm using the csc 250 skimmer and it works great for my system, although i think they have discontinued that model :sad: As for the DC pumps they are pretty good pumps, just thier controller power supplies are garbage, and to be honest when I had my dc pump i never once adjusted my pump level.

[mikellini]

Fair enough, but I don't conceptualize the point. Seems odd to want a controllable pump that I don't want to change. Just start with the right sized pump and go.

But, I've been known to be wrong before. Not often, but it happens :razz:

I just have no interest in fiddling with things, I want to plug it in and be done with it.

Chances are, you won't change the pump speed after initial setup as long as your bioload doesn't change. However, the advantage is in that initial tuning, being able to set it perfectly to your bioload. Easier than trying to exactly match a skimmer/pump to your bioload based on manufacturer's recommendations, no?

[Aquattro]

no?

No :) I find that the water height and air intake are enough to perfectly tune for my needs, so I'd rather not buy a DC pump. More complicated, more stuff to break.

[mikellini]

Fair enough. AC pumps are pretty much a known commodity too, you can generally size a skimmer based on the wattage/output of the pump

[neoh]

I plan the tank based on swimming room, and I think that has a lot to do with the bioload. The detritus needs to be extracted. The more fish you have laying waste, the more problems you could have.

If you were locked in a small room with a lot of people, that place is going to stink and cause you problems. Locked in a large room with a couple people, you're going to have a better time and waste management won't be an issue. If you are locked in a big room with a lot of people, but have a better waste removal solution, you will be a lot happier and only worry about that one dude who keeps eye balling your girl, as opposed to the carpets festering, and causing an ebola outbreak.

Double the skimmer for the tank size (400g on a 200g system) - carbon, gfo, waterchanges, rodi, and only feed the good stuff once a week (mysis, blood worms, etc.), flake once a day and nori once every other day.

I think as long as the system has good turn over, with proper flow to allow small particles and detritus to be caught up into the sump, then the rest is maintenance.

I had an understocked tank and fed three times a day, I had algae and high nutrients with an underpowered skimmer. So now I have an overstocked tank, feed less and skim more, and have no algae, no problems and perfect parameters. I also stopped dosing the unecessaries like reef roids, and other filter feeding material and now maintain better water quality.

[pinkreef]

Did you get your new skimmer Brad?:question: what are you getting if not
Barb

[Aquattro]

Did you get your new skimmer Brad?:question: what are you getting if not
Barb

I have pumps coming in this week for the various bubble kings, I'll play with those for a while and see what I like. I might run dual BK 160s, maybe a 200. I have an Omega 150 and a Super Reef Octopus here to test. So not sure yet what I'll end up with.

[Samw]

I think it does address the question. Your question was how do you know if your tank has light, med, or high bioload: "How do we measure that? I mean, quantitatively, what's a medium bio load? Or heavy? Or medium light? "

So with a DO meter, measure your DO first thing in the morning before there is any light when DO is at its lowest levels. If DO is at 50% or less, you have a high bioload. If DO is 50-75%, you have medium bioload. If DO is 75%+, you have light bioload.

$150 is cheaper than many protein skimmers. Or rent one from a lab: http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=7&cad=rja&uact=8&ved=0CEAQFjAG&url=http%3A%2F%2Fwww.myhoskin.com%2Fnewsletters%2F environmental%2Frental-cat-11.pdf&ei=pk3ZVJvuNcGuyASqzoDQDw&usg=AFQjCNHCbIkL5FbuGN8G8gRJtsrUHvDljg&sig2=1kD_1pZ12hTWDbiE64d4zQ




Ok, I'll give you that :)

However, that doesn't really address the question.

Skimmer x is good for 200g @ light load, 150g @ med load, 100g high load. How does one determine if skimmer x is appropriate for their 120g tank?

Personally, I've been doing this a couple years now, I just know. I know my bio load, pretty comfortable guessing bio load capacity, and I'm confident in my abilities to size a skimmer.
But for most consumers new to the hobby, what does that mean? Does skimmer x meet my needs? Or do I need x +/-1 for my tank? Generally bigger is better, but if I go too large, I may not have enough load to get proper foam development.

All theoretical discussion with no real answer, just something to kick around.

[Samw]

If your question was how to interpret a manufacturer's recommendation as to whether the skimmer is good enough for your bioload (once you've measured what it is), then nothing can of course resolve that since that is the manufacturer's recommendation. That is just up to the customer to trust the manufacturer and is simply a trust issue.