Powerheads and circulation on 300g

[Tj203]

For you that works. For him/her with a sump only 5 or 6' below the tank and only a 300g that's going to be way to much flow.

As it sits right now my sump is under my tank with 2 inch pvc and I get about 3200gpm and thats with the bigger impeller. I had the random flow generators on and I had to take them off because it was to restrictive. Don't think you realize how much head all the fittings add. When I do it from the basement I am just running 2 in pvc up and over the tank because of that. Also if you read my first post I stated without seeing his exact setup I could not tell. Also you can make it a little more efficient if you shut the output a little. Also depends on the stocking of the tank to i am very heavily stocked. As he stated he wanted a predator tank, you Usually need higher filtration for those tanks By no means do I think that pump is overkill for a 300 gallon. I would without a doubt run two on my 600. Would not even try with this pump from my basement. If you look at the flow chart right at 20' ahead is when it starts dropping gpm off alot.

 

[twentyleagues]

As it sits right now my sump is under my tank with 2 inch pvc and I get about 3200gpm and thats with the bigger impeller. I had the random flow generators on and I had to take them off because it was to restrictive. Don't think you realize how much head all the fittings add. When I do it from the basement I am just running 2 in pvc up and over the tank because of that. Also if you read my first post I stated without seeing his exact setup I could not tell. Also you can make it a little more efficient if you shut the output a little. Also depends on the stocking of the tank to i am very heavily stocked. As he stated he wanted a predator tank, you Usually need higher filtration for those tanks By no means do I think that pump is overkill for a 300 gallon. I would without a doubt run two on my 600. Would not even try with this pump from my basement. If you look at the flow chart right at 20' ahead is when it starts dropping gpm off alot.

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They want polys and dats. Even if they were using a crazy amount of 90s and other fittings let's say it all equates to 12' of head which is really pretty unrealistic that'd be 4500gph which is 15× turn over. I don't think polys or dats are going to appreciate that kind of flow. It will definitely keep the bottom clean! I know you started by saying it's a loaded question and we don't know their setup...and we don't. I wonder if the overflows could handle that kind of input?
I think it's be safer to aim for a pump with 5-10× turn over and a couple well placed power heads on timers to turn off during non peak activity like when the lights have been on for a while until just after feeding. I keep a ton of polys/ropefish (no dats) but polys are mostly nocturnal and as such mine are way more active in dimmer to no lighting. I have a 300g pond with 12 polys 14 ropefish and a few odds and ends. 2200gph into pond, sand, driftwood, plants. Algae coming off the sides accumulates in two low flow spots, easy to vacuum out once a week. Some of the ropefish enjoy swimming against the flow the others stay out of the main current. I tried the hammerhead when first setting this up. I have 2 1.5" drains and it overwhelmed them draining the sump. I am currently running a jebao 15000 at about 5' of head. This is perfect maybe a little to much at the output. I had a powerhead on a hook attached to the rim of the pond (to thick for magnets and I don't trust suction cups for that stuff), for me it is easier to just vac those spots real quick then to have the ease of it being blown into the water column to be carried into the sump.