Return pump - WHAT?!?

jda · May 22, 2019

Keep the current drain. Run a return line up and over the top with 3/4 inch tube and a something like this:
https://www.marinedepot.com/U_Tube_...MIrJTUhJuw4gIVWLbACh1fggGiEAYYASABEgJX3_D_BwE

Run another intake up over the top to another pump for a closed loop with the three returns. Get a stronger pump for this. Closed loops are awesome for flow and stuff.

None of those pumps need 3/4 inch. Once you lower the diameter, the head increases, but so does the power - output depends on the model and head height. We were able to get about 600 GPH up 20 feet with a Mag 12 with 1/2 line... at about 100+ watts (ouch). Mag 7 is a great pump for 1/2 inch and is 400-500 GPH at 4-5 feet of head. Ehiem are nearly all 1/2 too. You can move nearly any AC pump to a smaller neck size.

Aardvark1134 · May 22, 2019

Thats strange since the mag 12 specifically says no smaller than 3/4 inch and that it will cut off and not pump at all at 15 ft and that at 14ft it only does 170GHP... thats according to the manufacturer. I would like to see you get almost 4x the 14ft max through an even more restrictive line 6 ft higher than the pump can even do and 5 ft beyond the shutoff limit.

Fiesty · May 22, 2019

jda said:
I would skip DC if you are going to have restrictions like that. They are low RPM and made to move water without much back pressure. You could always size it up, but then you will kill any energy savings. Look low wattage AC like Mag, Fluval or Laguna, IMO.

Have you considered going over-the-top with your return and just making those three outlets into a Closed Loop? That would solve your back siphon issues too.

I was just going to recommend, as well, going over the back with return (to display tank water) and using existing cut holes for flow to the sump. Then have greater option on pumps and less options of wet flooring.

road_runner · May 22, 2019

Fiesty said:
I was just going to recommend, as well, going over the back with return (to display tank water) and using existing cut holes for flow to the sump. Then have greater option on pumps and less options of wet flooring.

I second that. DC pumps inherently weaker under head pressure. Unless if you go to high end ones like red dragon or abyzz.
If you have head pressure restrictions, AC will give you better flow...

jda · May 22, 2019

You should see how far you can push water in airline tube with a Mag Pump.... four stories. It is simple hydrodynamics... or you can just try it like many people do. The same is true with Iwaki or PanWorld... cut the output diameter size and the head increases and in some cases, so does the flow. You are thinking only that static pressure would decrease with the lower pipe size, but the dynamic pressure increases when you lower a line size with adequate power behind it (AC pump).

Mariette · May 22, 2019

Aardvark1134 said:
Jda I checked everyone of those brands and not a single one can push 550gph @1.5meter through 1/2 inch. They need 3/4 inch...with that said I think he prob has 3/4 inch and doesn't realize it.

*she* and yes. 3/4 inch. Boy is my face red hehehehe