Sump plumbing overflow valve placement

[Lonewalkerr]

I’m setting up my first stump and I want to know the best placement on my overflow valve. I put it near/in the sump (see photos) above where the Reefmat will connect. It’s a pretty tight fit and by doing this, I’m losing 2 to 3 inches in the sump, but that’s OK I guess since it goes: Reefmat > Skimmer > Bubble trap > Return. However, I’m considering putting it behind the tank, how bad of an idea would that be?

 

[UncommonSense]

Just move the gate valve back one fitting, so it sits horizontal instead of vertical!

This clears up wasted sump space, and keeps the valve fairly far down in the plumbing! — the latter is important to make tuning easier; a taller column of water backed up behind the gate valve restriction is easier to tune a consistent siphon from!

 

[Lonewalkerr]

Just move the gate valve back one fitting, so it sits horizontal instead of vertical!

This clears up wasted sump space, and keeps the valve fairly far down in the plumbing! — the latter is important to make tuning easier; a taller column of water backed up behind the gate valve restriction is easier to tune a consistent siphon from!

So I decided to raise the piping up so I would have clearance. I do see your point of view though. I have more piping so I’ll try the horizontal route, I just feel if it was back one fitting it’ll be harder for me to adjust. How often does this valve need to be adjusted? I assume it’s only once?

 

[UncommonSense]

So I decided to raise the piping up so I would have clearance.

This works fantastic too, honestly!

— the only note I’ll add is that you do want the end of the primary drain pipe to be submerged in the sump! This prevents the siphon from starting and stopping, and helps make the drain silent!

I have more piping so I’ll try the horizontal route, I just feel if it was back one fitting it’ll be harder for me to adjust.

I think it’ll be just fine raised up where you currently have it!

How often does this valve need to be adjusted? I assume it’s only once?

It depends on numerous things, and every custom plumbing job is unique; but adjustments are usually very occasional, and primarily for noise control!

Usually it’s case of set and forget until your return pump gets really dirty, or there’s low water in the return pump chamber! (Return pump starts flowing less than usual)