So im trying to wrap my head around something. I went to the local fish store yesterday to get a new pump the koralia 1 (which IMO sucks, says 400gph i doubt that), well they had a 35gal cube on display. It had a good assortment of riccia, hc, pellia, ect... I tried to find any sort of flow rate and to my surprise saw none. Not only did i not see any water movement the entire tank was pearling out of control. Only alge was a little slime stuff on the bottom. I asked the guy and he said it stays like this all day every day. So.... why is it that a tank with 0 flow has great results/little to no alge, and our tanks with as much flow as we can get having a hell of a time?

Obviously I can't answer the question without knowing more about the tank, but for sure, with low light you can have little to no algae without a lot of the things we know are essential with a high light tank. Light is the primary "cause" of algae, when you get down to it.

they had a 2xPC light. I dont know the exact Watts but from looking at it and the tank size they are for sure running 3+wpg.

If I were running a LFS and wanted a display tank, I would do heavy maintenance on it every morning before the store opened, possibly with a big water change each time, to keep it looking as clean and algae free as possible. Any bit of algae I would find I would remove immediately, and replant any plant that began to get algae. I can't say they are doing this, but it is what I would want to do.

how would daily water changes cut back on alge? Also why the intense pearling and great growth? I have seen this tank numerous times as i go about 1 a month. Every single time there are signs of great growth rates and no flow rate.

Are there any fish in that tank? With no fish you can jack up the CO2 dosage as high as you want, and assure that there is enough for all plants, even with little water circulation.

Daily water changes would allow you to over dose fertilizers as much as you wantedd, would maintain very clean water, and give you good access for cleaning the tank in general.

But, this is just speculation.

there was an assortment of shrimp and fish in the tank. Around 20 shrimp and 5 fish. They were all small species. I did not think about daily WC im sure as a fish store they are doing them every few days. Thanks for the info VaughnH!

Are there a fair amount of floating type plants?
Riccia alone can mop up most tanks by simply blocking the light.
Same for duckweed etc.
Current is where you need to mix the CO2 and under higher light.
At low light, CO2 is less important.


Regards,
Tom Barr