Planted FW tanks, substrate, pH and CO2 questions ..
 

I should ask this on a FW forum but what the heck let's put some activity in this one .. :lol:

I have a planted FW tank, must be coming up on 5 years old, and there's something I've never really been able to understand with this stuff.

I inject CO2 to try to have better plants than algae. For the most part it does not work out. For one, I can't seem to lower the pH of the tank .. at all .. with CO2. In fact, the pH is much higher in the tank than the tapwater is coming out of the tap.

Tap water is around 7.5, the tank runs around 8.5. This is with about 2 bubbles per second CO2 into a cyclone style CO2 reactor inside the tank.

Could the substrate be the cause? I have a mixture of black flourite and a laterite based substrate. Looked like crushed lava rocks though, if that helps.

A couple pieces of mopani driftwood are also in the tank.. could that be helping push the pH up?

I have a couple TLF phosban reactors kicking around somewhere, would it be a good idea to add peat pellets to help bring the pH down? If I do that, how do I know how much CO2 to add to the tank if I aim for a pH target based on the carbonate hardness of the water? (Or would peat bring the KH value down?)

I'll be doing some reading tonight in an effort to wrap my brain around these questions but I'd totally welcome any insights from planted tank gurus .. please and thank you!

What are you using for a co2 reactor (inline/in tank)?
120 bpm in what size of tank?
how much light?
What are you using for filtration ( canister/hob/sump )?


The substrate (fluorite/laterite) won't be the issue and I doubt the dw would affect it much...

I would check all your filter outlets and make sure they are well below the water surface. If you have a lot of surface agitation, lower the outlet even more or fill the tank up more. Are you using a co2 drop checker with 4 dkh water and ph solution to measure the co2 levels?

Ph is also very high for me out of the tap. I use a ph controller to drop my levels down to 7.0 which gives me about 30ppm. I also have lots of circulation throughout the tank (two canisters on my 90). Are you running the co2 on a timer or a ph controller? If you want a ph controller, I can trade you a milwaukee unit for one of those tlf reactors. :wink:

Not sure why the ph is higher in your tank. Do you have any limestone in there? That would definetely do it.

Thanks for the thoughts guys.. I don't have any limestone though. Yeah I did some more reading and came to the conclusions that neither the substrate or driftwood could explain the high pH. The only thing I can think of is that this tank kind of dropped off my radar for a while and I didn't do waterchanges for a long time (several months) and in the meantime just topped up, so maybe it's been building up for a while.

I kind of kicked my own butt into gear over this over the holidays and have been vaccuuming and waterchanging like crazy so I would have thought by now the pH would be closer to the tap water going in, but maybe I have more to go.

Is filtering through peat a good idea?

I'd take you up on the trade if you like, I don't have a pH controller but I do use a Milwaukee pH meter for checking pH. It's probably due for a probe replacement but I don't think it's shot seeing as I get plausible (and different) readings on other things so I think the >8 pH is probably correct.

So being without a controller, I just set the bubble rate to be reasonably steady and I watch what it does to the pH. When I first started injecting CO2 I found some chart online that matched target pH's to KH readings so I would just find a bubble rate that got me into that ballpark. I'd just increase the bubble rate right now except that I don't see any evidence it's pulling the pH down so I'm not sure what to do.

The tank particulars - 65g, has a sump, bioball tower. The CO2 is from a 20lb cylinder, the regulator and bubble counter are Milwaukee brand, and the reactor is a Red Sea cyclone mixer (this thing) .. I want to eventually upgrade to one of these.

Lights are 4x39w t5's, although I have 2 of them turned off for the moment until I get things straightened out.

I did have a Tunze 6055 for extra circulation in there but I've taken it off for now too in case the agitation was causing the CO2 to gas off out of the water too early. Although it hasn't made much of a difference so that's probably not it. I have a bunch of small tetras though and they seem more comfortable without that extra flow so I might keep it off anyhow. It was there for the loaches in there originally but they don't seem to be minding the lessened flow either.

The sump is your problem IMHO, you're gassing off your CO2...When injecting CO2 you really want to minimized your surface tension/agitation.

If you're looking for that AM 1000, they work excellent, I've run allot of reactors over the years and this one is by far the most effecient IME, I have a few of them, one is BNIB and can be had for half the price if you want it...I bought it for a new system build but then decided to try my hand at saltwater instead of another hitec planted system...

Filtering through peat moss would lower your pH. That's what a lot of discus-keepers do. We don't in the Lower Mainland usually because our pH is low and our water is "soft".

Also, as cale262 stated, reduce your overall surface tension and flow in the tank to allow the CO2 longer time to work in the water column before being dissipated into the atmosphere.

A lot of us locally are using Metricide instead of CO2. Its a concentrated form of the "plant food" Flourish Excel (double the strength) that is used to sterilize stuff in the medical field I believe. There's a local source for Metricide and its about $20 for a gallon which will last a very long time. I manually dose Metricide twice a week and the plants grow like crazy on it.

Anthony

And this metricide eliminates the need for injecting CO2 then? Interesting, will have to read up on it. I thought the whole point of CO2 is that most plants aren't meant to be submersed 100% of the time. I thought you couldn't compensate for that with more fertilizer or plant foods.. :neutral: ..

I guess what I'm not explaining very well is that what has me stumped is not that "it takes a lot of CO2." I understand I'm losing CO2 due to the sump. What has me stumped is that no amount of CO2 makes ANY difference.

Let me explain - in the past, although it took a lot of CO2 to lower pH, the CO2 DID lower the pH, there was a measurable difference between CO2 on and CO2 off. Currently what is happening is that it doesn't matter how much I add, it makes no difference to the pH. The equipment hasn't changed (same reactor same tank, just a different point in time). I was just trying to seek out potential causes for this change and thought maybe it was because the carbonate hardness seems inexplicably high as well.

I've even reduced the surface agitation quite significantly by removing the Tunze and it made no difference.

Unless I have a cylinder of just raw air and not CO2 maybe, but it was filled from the same fire extinguisher refill place I've used for the past decade so I have no reason to suspect that this is the cause.

PS. Cale I'm sending you a PM..

The Metricide goes through some sort of chemical reaction that releases carbon and reduces organic buildup in tanks.

If you check out how much to use of Seachem Excel, then half that dosage when applying Metricide.

Hey Tony, I have the same Red Sea co2 reactor and it does a very good job. But you have to keep it clean which means washinging it out every 3 weeks. Since you haven't done a water change for a while, i'm sure it's efficiency has been minimized.

Actually, a lot of plant people are moving over to sumps. You do have to crank up the co2 a bit but it should still be measureable (unlike your circumstance). Tom Barr (estimative index - plant guru) has a thread on his site going about his own tank with sump. It's been doing very well and he has no problems optimizing the co2 levels.

I would keep that Tunze turned on, just don't point it towards the water surface. You just want enough surface agitation to move a few circles around. With your overflow, there is no need to worry about any scum build up.

How is your drip plate setup? Is the water tumbling into a filter pad and then dispersed via a drip plate?

I read up on the phosban reactor and it is too small to run GFO on a 120 gallon system. Unless you want to trade both of them. :lol:

I dose the full Seachem line up with the exception of Excel and Flourish Trace. The Excel is not as effective compared to pressurized co2. But is an option.

Try cleaning the reactor first. You can completely dissassemble the clear plastic part. the bottom round circle needs to be pulled off with pliers. You need to take the impeller out and give the motor a good rinse too. Then dial your co2 to 2 bubbles per minute. I like to put vegetable oil into my bubble counter verus using water. Refill your co2 drop checker/indicator and check with again in 24 hours.

Water flow and movement is very important. The more circulation the faster the co2 can spread. It sounds like you don't have a drop checker and are measuring with a test kit?

Actually I do keep the reactor reasonably clean. It's more a question of being forced into it - I have these little snails (ramshorn maybe? But tiny) that get in there and jam it up otherwise, so I have to take it apart completely to get those things out of there.

When I reset the CO2 initiative, I soaked it in a mild muriatic acid solution because it was covered in algae. Hair algae is the bane of this tank's existence and scraping it off wasn't cutting it (well, poor choice of words, it was ONLY cutting it, only for it to come back quickly). After its little bath there it was spotless and shiny and remains so still luckily. :lol:

This is good to know, thanks. It's funny but I totally took this FW tank and applied a reef tank mentality towards it. It's been reasonably fun except when I had itty bitty fish keep going over the overflow. Between adding mesh to the overflow and not getting too small a fish it's gotten better.

Yes this is a nice benefit to this approach.

Exactly as you describe - filter floss and drip plate.

2 bubbles per minute? I don't think I can dial back my regulator and needle valve that much.


Er .. no, I'll say no since I have no idea what a drop checker is. For testing pH I've used both a pH test kit and a pH meter. Had the pH meter from the days of running a calcium reactor on the reef tank, same reason I have the 20lb cylinder actually.

What is a drop checker, can you post a link by any chance? (I'll google for it too in the meantime but please and thank you anyhow :) )

whops, I meant bubbles per second.

http://greenleafaquariums.com/co2-drop-checkers.html

Oh ok, that makes more sense, thanks :lol:

Thanks for the link too - very interesting stuff. Do you use one?

You bet. I sort of thought everyone did. They are really cheap. I got mie for 5 bucks shipped on ebay.

I say get rid of the sump personaly, you don't want the surface to be turbulant as this will off gas the co2, but ypou can modify it to work. I was actualy thinking of going with a sump for my next one. just going to take a lot to make the surfce still.

If you have a PH meter you don't need a drop checker, they are neat but just for people who don't want to spend the money on a PH meter. I got a PH controler for my tank when I set it up.

the reactor you are using isn't the best, I would go to a proper reactor style I got a bunch of new stuff to set up my freshwater tank just befor I moved.

if I am allowed the mecca of freshwater parts and supplies
http://www.aquariumplants.com/

I used 100% florite for my tank but I like the black look, makes the colors of the fish and plants pop, but this shouldn't be a problem for you. something is raising the PH.. a planted tank will always tend to drop in PH so you have something that is adding hardness and PH to your water so that is where I would look.

what are you adding for food, fertalizer, you putting any calcium based rocks in there for display? any rock that will fizz when you put vinager on it should not be in your planted tank.

Steve

If I move up this tank I'd probably lose the sump. For now it's pretty much kind of stuck the way it is. At some point I'd like to move the loaches over to a bigger home (they're about 12 years old now, I got them at 1/2" sometime in the 90's :eek:) so it's on the horizon at some point.

When the tank is cleaned up it actually looks really good with the black substrate (I have black Fluorite or whatever it's called as the top 1" or so) and a black background. Right now though what happens is the hair algae is growing too fast so it only looks nice for about 3-4 days after a massive tank cleanup. I've swapped over the driftwood to new pieces because I just couldn't scrape the old ones clean so for now the old ones are out on the deck getting the algae freeze-dried into oblivion (hopefully anyhow, I don't want to toss them, they're otherwise fairly nice pieces)..

I'll change out the reactor and see what transpires. I kind of think that the one I'm using just isn't up to the job for this particular tank.

Oh .. fertilizer. Right .. Umm .. unfortunately I've fallen behind on that. I used to get all my FW stuff from one shop in town which closed down and I need to do a better job of looking for FW planted supplies when I go LFS hopping.

Do you use a liquid fertilizer or the tabs that you shove into the substrate? Any suggestions for a kind to look for next time I make the LFS rounds?

Correct me if I'm wrong but I seem to remember reading that Tom was having issues with co2 and corrected it by sealing his sump, making it mostly air tight utilizing plastic sheets and duct tape...which may be worth the effort if you are keeping the sump.

I totally agree with the black fluorite, really makes things pop...

Here's one on my planted system pics with the blackflorite sand on the left side...

http://i251.photobucket.com/albums/g...s/IMG_1449.jpg

Just looked into it and yes you are correct. He sealed the wet/dry trickle part.

Got a link to that by any chance? I'd love to read up on that.

Awesome looking tank btw, I like the look of the two different substrates. I wouldn't have guessed it would look so congruent but it has a nice flow to it.

Those cherry shrimps - I'd love to try them but I fear they'd be clown loach food. Is this a baseless concern, should I try some?

Here is a link that explains the co2 to air loss. He is known as plantbrain here.

Here is his latest journal. Click on page #4 to see his sump.

ok couple things I see, are you using real drift wood from the ocean or are you using the mopani wood? If it is drift wood, thats probably leaching into your tank and raising your hardness.

I could never grow algae in my planted tank, do you have a nice mix of fast and slow growing plants? I did both fertalizers, jobe sticks in the substrate and home made pmdd. there are plenty of sights for home made reactor style co2 difusers that use bioballs, I am just using a media reactor (red one from my excess salt water stuff, can't remember who makes it) and a bunch of bio balls. I have it set up to hang on the outside of the tank. I used a fuval canister filter for my fresh water tank, so the ouput of that is going to feed the reactor then I use a subsurface spray bar to put the water back to the tank. the top of my water is dead calm but there is quite a bit of flow under the surface.

Steve

I have the same substrate black crashed Haitian moon. PH is always high.
But plants are happy with Co2 injection. what i do is i inject Co2 in to outside canister filter intake. It all get 100% dissolved by the time water comes out of the filter, nothing fancy but works well.
recently changed to low wattage LED and plants love it !
TDS is about 400 ppm
And for algae control shrimps are always the best. I have painted fire shrimps multiplying and some times being eaten but micro algae is under control.

Hi Steve, it's actual Mopani ... er, I think. Come to think of it it might have been labelled Malaysian driftwood. I'm not sure if that's the same thing or not. :redface: At any rate it's purchased and not collected. Many years ago I did try using pieces of wood I collected out of streams in the mountains but the stuff would get moldy so that experiment didn't last too long.

Here is what i use but not regularly
http://i381.photobucket.com/albums/o...6/IMG_0128.jpg

Tony, you can buy from green leaf aquariums. It's much cheaper than any hydroponics store in Calgary.

The only Seachem that I buy is the iron. We have hard water so the iron chelate that you can buy in the fertilizer does not last as long.

are you running carbon? Mopani should stain the water and drop the PH, your introducing hardness somewhere....


Steve

Yeah that is the weirdest thing, the water does not stain with tannins, but there is no carbon. When I presoaked the wood for a couple days it made that standing water super brown, maybe it leeched enough that it doesn't stain anymore, but that just seems odd to me nevertheless.

I have probably about 3 gallons of plastic bioballs in the sump and over top of that is some filter floss. Other than than the Tunze that is really it to this tank. I do use a cable heater in the substrate but I don't imagine that has anything to do with the lack of tannins in the water.