Help with sump, redesign existing sump or build new one.

[uf-engineer]

I have a 20 gallon high, 24x12x16, refugium / sump. I’m upgrading my display tank and would like to add an in the sump skimmer. I’m considering two options:
(1) Drill the 20 gallon on the return side and add a drilled 15 gallon. I would drill each tank on the side glass and add a bulkhead to each tank connecting them. Would one bulkhead be enough to accommodate the flow from one return from main tank (I would think so)? The 15 gallon, 24x12x12 or 20x10x18, would house an ASM G3 w / recirculation.

(2) Strip the existing 20 gallon reusing the bubble traps. Purchase a new 30 gallon long and recreate my sump / refugium to accommodate the G3.

With option (1) I would be able to remove the sump, if need be, by disassembling it. With option (2) it would be down right impossible to remove the 30 gallon without (a) empting the display tank or (b) removing the center brace on my wooden stand.

With option (2) I would be less susceptible to leaks.

What do you guys/gals think? Option 1 or 2. If option 1, would a single one inch bulk head be enough?

Thanks
MC

[reverendmaynard]

Option 1 sounds pretty good but there are a few issues. My sump is made from three rubbermades connected by 1.5" pvc, so I think I have some insight into those issues.

You're going to need to go larger than 1". Personally, I'd go with 2". My sump only flows about 500gph, and the 1.5" pipe is a bit of a bottleneck. If I go with any more flow, the water level in the bucket that receives the overflow starts to rise. I guess horizontal pipes don't flow that well unless they have some pressure behind them. Consequently, the water level in that first bucket is a couple inches above the outlet pipe. This leads to surface scum collection. I don't find this to a big problem, as I'd rather have it collect there rather than be remixed into the water. I then use a plastic cup to skim off the surface when I do my weekly water change. Clever positioning of the skimmer output would probably fix that.

If you use 2" pipe with a true union ball valve in between, you'd be able to regulate the flow and set the water level where you want it, which can be important for in-sump skimmers. If you go too small, your only option is to slow the flow going in.

[dj synystr]

any reason whny you want an in sump skimmer? do you not have room for an out of sump skimmer right next to the sump under the tank?

[sjm817]

Id go for the 30L. I removed the center brace (very easy) and I just leave it wedged in there now. I remove it when doing any work in the sump area.

[uf-engineer]

I'm upgrading from a 75 gal to a 90 gal tank. How stable is your stand when you remove the center brace? What size tank do you have