Really noob question

[Wolf89]

Sorry, I am really new, but I have a question. When you have an overflow, with holes at the bottom for a plumbing, does that area fill with water or is it watertight?

 

[Wolf89]

Also, when dosing, do I do it in the DT or the sump? Or the overflow?

 

[ccombs]

Sorry, I am really new, but I have a question. When you have an overflow, with holes at the bottom for a plumbing, does that area fill with water or is it watertight?

Not sure exactly what you are asking here, so I will broadly address the overflow.

The holes will be plumbed to a sump using a bulkhead. This bulkhead will typically have a gasket and completely screw on.

If done correctly, every connection in an aquarium should be watertight.

 

[Jekyl]

Vents in the top of the overflow sit just below the water line. Water drains into the box and then is pumped from the bottom holes to the sump. The return pump inside the sump keeps the water level in the DT high enough to drain into the overflow. Dosing is best done onto a powerhead that will disperse it quickly.

 

[Wolf89]

I mean does this area in red fill with water?

 

[Jekyl]

Looks like it. There's holes drilled at the top to allow the water in

 

[ccombs]

I mean does this area in red fill with water?

Oh! Yes, it does. See attached picture for very popular overflow scheme.

 

[WVNed]

Yes It does

 

[Boltline]

Yea brotha, you're good. You want to have the water come pass the elbow. The mesh tube is there to protect your live stock from making it down into your pumping. I would suggest you add it to your cleaning schedule to make sure it doesn't clog.

 

[Sod Buster]

I would personally take that mesh right out, or black out the glass on the overflow box. That is going to be a hair algae mess and clog.

You also have a "durso" style drain if you want to do some reading on how to quiet them down and manage the air bubbles in the sump.

 

[Sod Buster]

Looking at it again with less tired eyes, I would also drill a hole on each side of the tee at the waterline. That allows the scum or shiny film that floats to enter the drain and be skimmed out or mixed back in.