New Build Plumbing/Flow Help

[Regulator23]

1st post, thank you for your help. I have 2 reef tanks (125G and 110G) that I am about to consolidate my fish and corals into a new acrylic 180. The 180 is peninsula style (viewed from 3 sides) with a single overflow box on one end. In the overflow box, there are two drain holes that will accommodate 1 1/2" PVC and a single return hole which will accommodate a 3/4" PVC. Here's where I need help. 1st question is do I really need 2 giant drain holes/standpipes? My pump will do 4,100GPH, but with only a single 3/4" return, am I going to push enough water to warrant the 2 standpipes? Or is there another use for a 2nd drain/standpipe? FYI, My sump has the input holes for both.

Next question is the return hole. Do you think it would be advisable to drill it larger to accommodate maybe a 1" PVC? Both of my other tanks use a 3/4" but I don't have nearly as strong of a pump on them. Anyway, that's one question/dilemma.

The second is regarding my pump and other plumbing. There are 4 pieces of equipment that I want to plumb in and was thinking to plumb them all off of my main pump (it's an in sump pump). My chiller and UV don't need a lot of flow and I would use 3/4" hose for them and run them on the same loop. The other 2 are my calcium and GFO reactors which have 1/2" hoses and require very little flow. I was thinking of just plumbing them all on my main pump and using valves for the necessary flow. So the question is, will that take away too much from my tank flow? The head height on the tank is only about 6 feet.

Last question is regarding my new sump. It has 3 compartments, first, the drain pipe input which is small, then a second area which I was going to use as my refugium and then the 3rd where my pump would go. The 3rd area is plenty big to also accommodate my protein skimmer, but is it OK to have the protein skimmer in the same area as the pump. Again, there is plenty of room for both.

I'm sorry for the long post but wanted to be as clear as I can. Thank you for your thoughts.

 

[Fudsey]

I can answer a couple, 3rd question 1st. You don't want your skimmer with your return as that is the chamber that will fluctuate in water depth.

2nd question, you could make a manifold with multiple ball valves/outputs to regulate flow to chiller, UV,...

 

[George Lopez]

I will start by saying that I am no pro and don't pretend to be but here are my $0.02

1. The second stand pipe is an emergency overflow which will hopefully never be used. At 4100gph I would keep it as just that in case something happens with your main drain. Second 3/4" return? Sounds small to me but I don't have a big tank so what would I know.

2. You can make a manifold and run your accessories off of your main like many people including myself do. Your pump should be strong enough to be able to take the accessories. Like you said they don't take much to run them.

3.

The skimmer needs a stable water level and the return pump area is where you will notice your evaporation water plus you will not have a bubble break so you will probably get bubbles running into your dt. So I wouldn't recommend that door for your skimmer. I would see about maybe adding another compartment for the skimmer where you can keep your water level controlled and habe a bubble break to not get micro bubbles in the dt.