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View Full Version : To baffle or not to baffle?


Aquattro
10-22-2010, 05:30 PM
In discussion yesterday with LFS, the thought of baffles came up. It was suggested to not use any to allow greater room. So if I'm using a herbie overflow with no bubbles, what are the advantages of baffles?
Who doesn't use them and is happy with their sump?

lastlight
10-22-2010, 05:32 PM
My drain runs into a filter sock and is absolutely bubble free. Then comes the skimmer compartment. Baffles keep my display virtually bubble free. I think they do entirely actually as I'm still getting bubbles releasing from the remains of the diatoms on the sand and rocks which get powerhead pureed.

Say yes to baffles! My middle baffle is the one that is raised a bit off the sump floor but I think everyone does it that way.

Aquattro
10-22-2010, 05:38 PM
Ya, my current sump has a set at the end to reduce bubbles and keeps the return pump chamber full, but it's 5' long and has lots of room. My new sump will only be 4', so I thought of going without. Not a big deal, as the old sump needs to have them removed and they'll drop right into the new sump, but I thought I might have more options without...

blacknife
10-22-2010, 05:43 PM
i vote for.. although not nessisarly lots of them.

I cracked my last sump while tightening a drippy bulkhead. only the water in the return chamber leaked on my floor. I would say at least one set before the pump just incase anything crazy happens.

sphelps
10-22-2010, 05:44 PM
On my last 100 gal tank I just had an open tank for a sump with just a skimmer, no baffles at all. I used a herbie style drain and didn't get any bubbles at all. It's important that your skimmer also doesn't allow air bubbles to exit otherwise a baffle or something may be require for that. Provided you don't have any source of air bubbles and don't require specific water direction travel baffles serve little purpose.

I did it mainly for simplicity and laziness but it would certainly give more flexibility for equipment changes/additions. You could also build removable baffles very easily.

Aquattro
10-22-2010, 05:49 PM
Hmm, my skimmer would introduce bubbles, hadn't thought of that..oops :)
Plus, I'm using a 75g that will have the brace removed, so I guess baffles would lend some strength as well...

lastlight
10-22-2010, 05:51 PM
So far I haven't had a skimmer that didn't release micro bubbles. ASM, BK and now SWC. I've often thought about tossing a sock on the out-take but wondered if the back-pressure would affect the skimmer.

sphelps
10-22-2010, 06:02 PM
So far I haven't had a skimmer that didn't release micro bubbles. ASM, BK and now SWC. I've often thought about tossing a sock on the out-take but wondered if the back-pressure would affect the skimmer.

My BK doesn't release a single bubble, perhaps your water level was too high?

Delphinus
10-22-2010, 06:27 PM
Hmm, my skimmer would introduce bubbles, hadn't thought of that..oops :)
Plus, I'm using a 75g that will have the brace removed, so I guess baffles would lend some strength as well...

I've got a Herbie on the big tank and baffles and that was the rationalization I gave myself for doing so. I did go with fewer baffles in v2 after the walls got cracked and I'm happy with that decision.

My 40g tank uses a 10g sump without baffles and it's just a straight standpipe open at the top and the BM100 skimmer I use dumps bubbles like crazy. And yet no microbubbles in the tank - the turnover is just right apparently.

My 115g tank has a 28" sump and dual overflows (kinda silly on a 30" tank, but it is what it is) and baffles AND a filter sock can't completely eliminate microbubbles. I hate having baffles down there, it is one tight sump to work any equipment into.

How long will your new sump be, and what kind of volume do you think will be travelling through it?

Aquattro
10-22-2010, 06:30 PM
How long will your new sump be, and what kind of volume do you think will be travelling through it?

Tony, it's a 75g, 4' x 18" footprint. I expect I'll push 1000gph max through it. I'm using 1" pipe for my herbie, so no crazy flow.

globaldesigns
10-22-2010, 06:44 PM
I guess it would be determined by your design. My sump has to baffled areas and they work for me.

Benefits as others stated:
- fewer to no bubbles in DT
- if leak happens, it may limit damage to outside of tank by compartmentalization (Wow big word, probably spelled wrong)

If the above doesn't come into play for you, then I think you could free up space for other things, like all those nifty gadgets we all want.

Phanman
10-22-2010, 07:10 PM
Id put one baffle in the sump and have a valve on it so you can control the water level in one compartment for the skimmer. I think this works better then building a stand for your skimmer.

Aquattro
10-22-2010, 07:12 PM
Id put one baffle in the sump and have a valve on it so you can control the water level in one compartment for the skimmer. I think this works better then building a stand for your skimmer.

In hindsite, that would have been a good idea for my current sump, as I had to lift the skimmer about 6 inches. The new setup should work with the skimmer sitting flat in the sump, as I need to keep height down.

shrimpchips
10-22-2010, 07:45 PM
I have baffles in simply to allow for different water levels within the sump - it was the only way I was going to have 10"+ of water for my skimmer to sit in, but still retain enough empty volume in the sump to allow for the drainage from the DT when power goes out or the return pump requires maintenance. There's no bubble traps though, as with a modified herbie and BK skimmer, I don't expect to have any bubbles going on in the sump anyways.

Also, it allows me to have a little frag area in a small 25g sump.

PoonTang
10-22-2010, 08:15 PM
You can use baffles to keep a steady level for your skimmer to operate at its best efficency and also to keep its bubbles out of the display. I would consider using reversed baffles like I do (see my build thread). It will keep the floaty scum from the DT in the skimmer chamber rather than skimming it off and sending it back to the tank, and because it takes water from the bottom of the chamber it filters out micro bubbles better. You can also get away with only having 2 baffles thus saving space.

StirCrazy
10-23-2010, 05:21 PM
you need at least one baffle, especialy since you refuse to use anything larger than 5 gal for top off. if you have the whole thing baffleless when your float valve opens it will drain your top off container. so you need to baffel a level control area for your top off, also you need to make the water level where your skimmer is constant, so a baffle to keep the water the right high there. so you need two compartments at least. putting a single baffle in the last 1/3 of the sump will keep the water the right hight in the first 2/3rds of the tank for the skimmer and the last 1/3 will fluxuate with your evaporation.

Steve

christyf5
10-23-2010, 05:27 PM
No baffles on my 70gallon sump. The skimmer is at the opposite end to the return which works great but I have to throttle my return pump back to slowdown the incoming water (which is located "mid-sump) in order to avoid microbubbles. To solve this I just run a filter sock that gets changed weekly and no problemo. I don't worry about the level in the sump as its controlled by my autotopoff and controller

Binare
10-24-2010, 12:54 AM
No baffles either. I make sure my drain pipe is completely submerged on both ends and let my ato take care of the level. I only run my sumps as refugiums.

Aquattro
10-24-2010, 01:38 AM
Ya, I plan on plumbing my RO in full time for ATO, so level is taken care of there. Just the skimmer bubbles left to think about

StirCrazy
10-24-2010, 05:52 PM
Ya, I plan on plumbing my RO in full time for ATO, so level is taken care of there.

Ok, so I am setting up a pool, $2.00 to enter. Pick the date Brad's sump overflows :mrgreen:

Steve

Aquattro
10-24-2010, 06:11 PM
Ok, so I am setting up a pool, $2.00 to enter. Pick the date Brad's sump overflows :mrgreen:

Steve

You're just still bitter about flooding your garage. And driveway. And neighbourhood....-lol

My ATO will be plumbed through a timer, so it will only operate periodically throughout the day....

christyf5
10-24-2010, 06:13 PM
Ya, I plan on plumbing my RO in full time for ATO, so level is taken care of there.

I thought that was supposed to shorten the life of the membrane??

Aquattro
10-24-2010, 08:11 PM
I thought that was supposed to shorten the life of the membrane??

I haven't heard that, but I've never researched the technique. Not sure how it would, most RO units are plumbed under sink for drinking water, to fill a 5g resevoir...tank application seems to be the same principle??

christyf5
10-24-2010, 10:17 PM
I haven't heard that, but I've never researched the technique. Not sure how it would, most RO units are plumbed under sink for drinking water, to fill a 5g resevoir...tank application seems to be the same principle??

True dat, but filling a 5g reservoir is different than the half inch change in level in your sump IMO. Then again maybe it just keeps the 5g full and it doesn't completely empty. I dunno, I just heard someone on here talking about it, maybe they'll see this and chime in.

PoonTang
10-24-2010, 10:36 PM
Running small volumes through your unit is hard on the DI resin due to TDS creep. When the unit is shut off the solids will cross the membrane as time goes by and when the unit is turned on this large concentration gets taken out by the DI. I now with my online monitor it will read about 25ppm at the membrane outflow upon startup and then settle to about 2 after a minute or so. I don't know what small volumes does to the membranes tho.

StirCrazy
10-25-2010, 05:20 PM
You're just still bitter about flooding your garage. And driveway. And neighbourhood....-lol

My ATO will be plumbed through a timer, so it will only operate periodically throughout the day....

hmm... I got nothing :sad::mrgreen:

but it was just the garage and part of the driveway :wink:

sphelps
10-25-2010, 05:57 PM
I thought that was supposed to shorten the life of the membrane??

Rapid shut off can cause cavitation in the membrane which can cause damage but a pressurized storage tank or accumulator eliminates this problem. So if you don't have a pressure tank or accumulator then you'll want to run your RO for longer periods of time less often to reduce the occurrence of possible damage.

Parker
10-25-2010, 07:37 PM
I have one baffle in my sump but only cause I'm too lazy to take it out. No micro bubble issues and my skimmer doesn't introduce bubbles. My auto top-off is manual at the moment but I'm planning on running a float valve in the sump backed up by a electric valve connected to a timer through my APEX.

lastlight
10-25-2010, 08:24 PM
If I'm filling my 5g bucket with ro/di with my membranes etc as is right now the rest I can get out of my membrane is about 7 TDS before resin.

Now that I fill a 45g tank every couple weeks it runs for many hours and eventually goes as low as 2 TDS pre-resin so that helps.

I also see TDS creep after having the water turned off for even 10 min. Since I started bypassing water until the TDS goes down I have made my very first portion of resin last since I got back into the hobby.

Delphinus
10-25-2010, 08:36 PM
At my old house I ran RO/DI to my tank top off valve full time but because the run from the laundry room to the tank was large, I had it fill a reservoir in behind my tank and the tank topoff was filled from that reservoir. The RO/DI was on all the time into this reservoir but because it was so far away (well 20' or so) from the filters, it buffered things just enough that I ran this way without problems for years.

Then I moved and now had a tank 5' away from my water source so I removed the inline reservoir and had the RO/DI direct to the sump. What a mistake that was. I ended up replacing my RO membrane 3 times that first year before I figured out that the problem now was the incessant cycling of the membrane. It would literally run for about 5 seconds every 5 minutes. Turns out this is bad for a membrane. Who knew!

So now what I do is run my RO/DI into a reservoir which then feeds my topoff downstream. I worry about filling up the reservoir maybe once every two weeks or so - I let it empty, or get near-to-empty, then I fill it to the top (letting the float valve shut the RO/DI off when it's full to prevent overflows). Since switching to this method I seem get about 2-3 years out of a membrane before I start noticing TDS creep that doesn't clear itself with an extra long flush. It's really the same thing as what a pressure tank does except instead of using a pressure based diaphragm to control the fill, I just open or close a valve to fill the reservoir in one big fill.

True dat, but filling a 5g reservoir is different than the half inch change in level in your sump IMO. Then again maybe it just keeps the 5g full and it doesn't completely empty. I dunno, I just heard someone on here talking about it, maybe they'll see this and chime in.

Running small volumes through your unit is hard on the DI resin due to TDS creep. When the unit is shut off the solids will cross the membrane as time goes by and when the unit is turned on this large concentration gets taken out by the DI. I now with my online monitor it will read about 25ppm at the membrane outflow upon startup and then settle to about 2 after a minute or so. I don't know what small volumes does to the membranes tho.

Rapid shut off can cause cavitation in the membrane which can cause damage but a pressurized storage tank or accumulator eliminates this problem. So if you don't have a pressure tank or accumulator then you'll want to run your RO for longer periods of time less often to reduce the occurrence of possible damage.

mark
10-25-2010, 10:51 PM
I'm doing baffles as was concerned about microbubbles when first setup (plus thought everyone else had baffles). Now that lowered flow could probably remove but why bother.

As for TDS have my ro/di feeding a float in my sump (I know living on the edge) and haven't noticed creep, though do have the reservoir tank.

Murminator
10-27-2010, 08:00 PM
What about some movable baffles then try what you like

http://www.wetwebmedia.com/ca/volume_3/cav3i1/Baffles/bafflesart.htm