questions on pump size

[digitalcowboy00]

I have a 55 gal, with a 10 gal sump, a marineland in sump protien skimmer, 50 lbs live rock and 2 #1 Korllia's. I had a mag 3 as my return pump, but I thought I needed more flow, so i got a mag 7. I had one return line back to my tank, but changed it up and added a Y so i have a return on both sides of the tank for more even flow. The only thing is, i see not diff in the mag 7 to the mag 3. Am I fine sticking with the mag 3 and returning the mag 7? and will the mag 3 give me enough return flow. any help would be greatly appreciated. Thanks Justin

[LoneStar]

The reason you do not see more flow from the mag 7 is because you placed the Y in the return. The flow, in essance, was cut in half to each return line. You are still achieving a higher flow rate down through your sump. I would not get a higher return pump since thats pushing it for a 10g sump. The faster you move the water through your sump, the less contact time you skimmer will have to clean the water. Plus, you do not want to overload your overflow setup with too much water.

If you want more flow in your tank, add another powerhead.

[swjim]

Have you considered using your Mag 3 as a return pump and hooking up the Mag 7 as a closed loop?

[digitalcowboy00]

What do you mean by a closed loop, sorry I am kinda new to this. The return pump is from the sump to my tank correct? So what is the closed loop pump for? Also is it good to have the Y in the line of just to have one return line on one side of my tank. Thanks for your help.

[swjim]

A closed loop means that the pump would draw water directly from the tank and send it back through one or more return lines, it would not go through the sump. The downside is that you would likely need to drill the tank to accomodate the drain line at least. You would have three options for the return:

1. Use use one or more of your existing return lines, you may need to expand the hole depending on how much flow you are trying to push through.
2. Drill additional hole(s) to accomodate the new return lines.
3. Plumb the returns over the back of the tank (doesn't look as clean but it saves you from having to drill the tank.

Obviously, drilling an acrylic tank is much simpler and safer than drilling glass. If you do have a glass aquarium, make sure the glass is untempered before drilling it, you should not drill tempered glass.