Is it a good or a bad idea to have powerheads in a planted tank? I have a 750 gph and a 250 gph powerhead that I have in my tank right now and was wondering if I should still use them when I go planted. I also have the sump return that provides some flow but not substantial with the head loss.
Right now, I have a saltwater setup in my 58 gallon with a huge carpet anemone, some gorgonians, anthelia, mushrooms, and some paly/zoa polyps. It is pretty low flow for a reef tank but I don't have anything that requires a lot of flow. I'm doing my research before I convert it to planted freshwater.
I only have dated pics. The tank has some algae issues now. I quit maintaining it after my last fish disappeared. The carpet anemones are bad for eating fish. I lost three fish to it and it's been fishless for a few months. All I have in the attached picture is my first gorgonian and you can see one of my clownfish in the top right corner.
There are definitely differing theories about sumps and CO2. My old fifty gallon had a sump and I can't say that I thought it was much different than the canister filter I have now. It was an enclosed trickle filter though, so I always felt that whatever was was coming out of solution was going to end up back in solution. I wouldn't say that was gospel in all situations though.
That's a nice looking tank BTW it'll look good planted.
I would suggest that your choice of plants and animals is probably going to dictate how much water movement you should have in your tank. Some species may not like fast currents, and some species might be in danger of being sucked into the impellers.
Since you have a couple of powerheads to choose from, as well as the more passive sump return, you've got the advantage of being able to experiment after you've got the rest of it set up and see how everything responds to it.
Another question I have is regarding surface water movement. Will the water agitation where water falls from the display tank to the sump cause too much agitation and decrease my CO2 levels too much?
If you are injecting Co2 in a high-tech set up, yes you'll lose a good amount via it gassing out. You can try to minimize it, but I think most people just crank up the Co2 to whatever it takes to overcome the loss and reach the desired ppm in the water column.
In a low-tech, non-Co2 enriched tank, agitation is always a good thing since it promotes gaseous exchange, and will actually raise the level of Co2. If that sounds contradictory, a non Co2 enriched tank is going to hover around 3 ppm - that's before any plant uptake. In that case you want all the agitation you can get to help maintain baseline levels. A high-tech set up will generally be shooting for 30-40+ ppm of Co2. At those levels any agitation only results in off gassing.
As for water movement in the tank, like others have said, ideally you want a gentle circulation all over, with no dead spots.
That's a nice looking tank. I hope you make a journal or post pictures somewhere once you get it going.
Actually sump is a good idea, you can hide much of the equipment, filter socks and even algae scrubber to minimize the algae in the main tank, and additional water volume. You just need to compensate for loss of Co2 due to excess water turbulence from the tank to the sump. You can't tell how much Co2 you need to inject until the system is up and running. You can even plant in the sump or extra holding tank for fish and plants, lots of possibilities. My next tank will have a sump.