physics lesson the hard way

[chris stevens]

so, i installed my bulkheads for my sump, got it up and running then realized i had made a ridiculous mistake. for some reason, all my "research" had led me to believe i did not need an overflow box, so i plumbed two 3/4" returns and a simple 1" drain in the middle, at the top of the tank. rigged it all up, looked beautiful. turned on the pump, no leaks! but then, i realized that my drain wasn't draining so well. thinking about it, it's obviously because there is not enough water pressure to force it down. whoops. can't believe i didn't think this out better before hand. would it be pointless to add another drain to compensate? should i plug the drain i have, drain the tank, drill another hole in the bottom and install a stand pipe? for the time being i've got one of the returns running with half of my pump pressure running back into the sump, and i threw a powerhead in to add some flow. arggh.

[ellisz]

What size pump are you running? My frag tanks just have a bulkhead drilled in the wall and have a 1" drain. They will only handle about 600 gph.

[chris stevens]

the pump is a mag 9.5 on a 55g, i know a bit overkill but i was planning on teeing it off so i could keep this pump if i moved up to a larger tank/larger overhead. still, can't imagine this drain keeping up with even like a mag7. I'm going to add another drain and a tee to the pump, see what happens.

[ellisz]

Depending on the head height, a Mag7 might be too much. I had to throttle back a mag7 on mine.

Something you could do is put in a T on the return line and create a discharge line back into the sump. That may the tank gets flow and what it cannot handle gets dumped back into the sump. I do this with my PCX100 in my basement. Since my overflow is limited on flow, I just divert some back into my sump. I also now feed my 20L frag tank and the 10 gal frag tank from the same pump.

If you can drill another hole, do it. I wish I had another.