Water flow/circulation in the aquarium

lildark185 said:

I am looking to increase the water flow in my aquarium in an attempt to eliminate bba. have an Eheim 2217, a HOT magnum filter and the Hagen elite mini (niko's DIY co2 reactor). How many powerheads should I have in a 55 gallon aquarium and what would be the ideal flow rate?

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I've seen BBA grow in low-flow and very high-flow areas, so I don't know if it's ever been proven that not enough flow causes BBA. Personally I had a 72g setup for years with just a Eheim 2236 (less flow than a 2217) and didn't have any bba or other problems. What is your lighting schedule and co2 levels. If you can I would increase co2, reduce lighting duration and stay on top of your filter cleaning possibily adding Purigen or other organic remover to your filter media.

I have 4wpg with lighting at 7hrs a day. I haven't measured the co2 level but it's approx 1-2 bps. I don't have any test kits and I'd rather not go out buying all of them.

Might I recommend the Hydor Korallia series pumps. these high flow/low pressure pumps come with a magnet mount and they are fairly affordable. You'll probably want to be looking at model #2 or #3.

lildark185 said:

I have 4wpg with lighting at 7hrs a day. I haven't measured the co2 level but it's approx 1-2 bps. I don't have any test kits and I'd rather not go out buying all of them.

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I don't know all the parameters of your tank, but are you running the 4 wpg all 7hrs. If yes, I would reduce if possible the other bank of lights to only 3/4 hrs, plus increase co2 if you can. I don't test anything either, but I run co2 as high as I can during day and turn off at night. I would say I'm running twice what you are on high-light tanks. Also doesn't hurt to stay on top of water changes and add purigen to filter.

I think bba is careless about flow. Most likely your problem is low CO2 than the flow. Get a drop checker with proper 4dkh solution and test it out. You are running pressurized right??

Also how is your dosing?

I agree the Koralias are excellent for increasing the flow around a tank. I have one so in my 180l tank so the flow (including the filter) is just over 10 times the volume.

However I agree with the others that BBA is most often linked to CO2 so unless your circulation is so poor that the CO2 rich water isn't getting circulated well enough I'd look at CO2 levels first.

You need a lot more co2. 1-2 bps will not even do in my 10 gallon.

when does co2 become hazardous to fish?