yeah I say there's a 90% chance you'll want to do things differently a couple years from now and get a completely different tank. Don't stress too much. I agree that an auto-top off unit is VERY desirable and an in sump skimmer is just fine.

One important thing is to consider is how to get water into the top off resevoir when it's in the stand. If the stand's not built yet maybe make it tall enough to get a small bucket into the stand to dump water in. Otherwise scooping water in with a little rubbermaid container SUCKS :)

Do you have room surrounding the tanks in case you want to add a refugium, another system, etc etc? If so then you shouldn't have to stress too much right now because you can add as you go.

Thats the only way I've had to rebuild twice,another tip dont go by manufacturers dimensions that was the reason for one of my rebuilds. I just bought a new skimmer and built the sump around it,the water level is perfect for my skimmer and doesnt fluctate because of special baffles, and I went with a lower tank to gain better access to my collection cup its a dream to work with trust me equipment first lol

heres another pointer setup the feed hose for your skimmer run it into a five gallon bucket and time how long it takes to fill,from that you can calculate your pump size. A little underpowered is good,it lets you adjust flow from the skimmer side because if you turn the valve on the pump side down you'll put strain on the pump due to backpressure and prematurelly burn out your pump

Hi Dab, is it a good thing to have a little less flow through the skimmer? And why?

If any flow needs to be turned down it should be the skimmer flow not the flow off the pump side so a pump that pumps a little less than the skimmer is better than a pump that pumps more than the skimmer make sense? When they sell pumps its rated by head (length of vertical pump) now if you also run this through a partially closed valve it increases your head/backpressure to a point your pump cant handle. This is all based on the fact that you will have a flow control valve on both the in and out lines in your sump

So it is preferable to slow down the flow after the skimmer? Have I got that right?

yes,the supply line for your sump just after the overflow/skimmer.


a SLIGHTLLY weaker pump will acomplish this for an example say your overflow flows at 310gph a good pump to use would be a 300. Dont forget to account for head for example I have 4 foot of rise from my sump so my pump needs to pump 300gph at 4 foot of head.......its easier than it sounds lol good luck

If you already have the pump that flows alot more than you need and you're worried about back preasure, just tee a line w/ball valve into the return and run it back to the entry section of your sump. You can then run your pump wide open and send any excess back through the sump

That sounds like a good suggestion. So we divert a portion of the flow off the pump back to the sump entry point from a point just after the pump output. ok.