Very confused on flow ratings for tanks

Michael Gentile

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Apr 4, 2016
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Ive been slowly upgrading my 55g bowfront tank, the dimensions are weird being 36in L, 20in W, 21in H. I was running two powerheads in it one pumping about 200GPH and a bigger one pumping 780GPH both fluval powerheads. Just today i added a red sea reef wavemaker 25. Im very happy with it and removed the smaller power head for the wavemaker. I was then thinking that i only really needed the wavemaker in there and the extra powerhead pumping 780GPH may be overkill. Its mostly a mixed reef tank and a lot of frags still. Im also only runnning the wavemaker at 60% max. I know it comes down to studying your rock and the flow of the tank and how things move. Each tank is different. But i see so many different takes on the right flow i was hoping someone could point me in the right direction. Can provide pics if needed.
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Apr 2, 2019
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Flow is good for keeping junk from settling on the bottom and sps especially like flow. So if your corals are happy and you don't think you have any dead spots you could be ok. Me I've always gone with a powerhead on each side though


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Jan 28, 2020
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Coral requirements aside. I think you basically just don't want any deadzones where detritus etc can build up or if you have a dead spot it needs to be easily accessible for cleaning. I also think turbulent flow is a good thing as well.
I know my fish like it. They often play in the flow...swimming towards the gyre then allowing the flow to float them back. They do it over and over again

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