Pumps

[Sato]

Is a bigger return pump necessarily better than a smaller one?
Also, if you cut the slot too wide in the pvc, will it still work? Wide as in the 1/8 inch part. My pipe cutting skills are subpar and made the slot a bit too large.

[SantaMonica]

As long as the screen is full of flow, that is all that matters, as far as filtering goes. This of course has nothing to do with flow in the display, which is dictated by the corals.

As over-wide slot will fill-in by itself with growth, which will slow the flow. So it might even out. Otherwise, you can pancake another layer of screen in that spot to fill up the slot.

[Eclip]

if you use a pump that has more flow then what you 'need' the extra slot width means little as long as the water makes it all the way to the end of your screen its fine. I found the wider my slot the more uniform the wall of water was. I think i have about a 5-6mm hole which is 1/4 inch to get full flow at 1000gph.

[Sato]

Ok thanks guys. Great site by the way SantaMonica. Umm, so the only way I could get a nice sheet of water over the mesh is to test it and adjust as needed?
Also, if I add another layer of mesh, will I need more lighting? I already have two layers by the way.
Thanks in advance.

[SantaMonica]

Don't add another layer. Actually one layer is best.

The screen will fill-in as growth occurs.

[Sato]

So should I take out the second layer? Here is my set up if this helps. I have 9x10 inch mesh x2. My tank is a 90 gallon with built in overflow. My sump is a 30 gallon tank and my pump is a mag 7. I'm afraid that the algae scrubber won't keep up if I have just one layer of mesh.

[SantaMonica]

One layer filters better for most people, because the light can reach to the screen.

[Sato]

One last question. Is my mag 7 good for the return or is it cutting it too close? The height is at 4'.

[SantaMonica]

If the screen is full of fast-flowing water, then it is good.

[Vannpytt]

My screen fills very well, but it's not possible to use the 3mm slot for a 85cm long pipe running 7k lph return. I had to widen the slot with a drill to make uniform holes. This works.

[Sato]

So I finally built everything and gave it a test. The water flows over the sheet very nicely. One thing is bothering me though, the part where the water comes down as a waterfall is making a lot of noise. Is there a way to remedy this?

[SantaMonica]

Put the screen in the water below.

[Sato]

The screen is already in the water below. The noise comes from the part where the tube connects to the canvas. I tried altering the flow but then the water would not come down as a sheet. Sorry! :oops:

[SantaMonica]

It will probably quiet down when growth occurs. Otherwise you can try a more narrow slot. Or reduce flow.