a few questions 'bout HOB overflows

[partypalooza5]

1) how do I keep it from gurgling like crazy!?!? The drain side of the box is too small for a standpipe I think... (1" bulkhead)

2) How can these things lose their prime? I watched mine today and i saw bubbles go through it but they were swept out, when I switched off the pump there were no bubbles in the tube (So I assume it will work again)

3) Should I leave a piece of airline in the tube connected to a PH just in case?

 

[jessicasmarine]

The gurgling never goes away bu to quiet it I jammed an old filter basket off a sump pump in the back above the stand pipe to break up the water flow. The gurgling is from the water forcing its way through the air, by breaking it up the air and water mixes and quiets it down.

I have never lost my prime so I cant help you there.

 

[jsoong]

As long as the water flow is fast enough, any small bubbles will get flushed out. This is a function of the siphon size vs. pump flow. When I use 2 1" siphons with my 750 gph pump <thinking maybe 2 is better due to redundancy>, I got air accumulation. Removing 1 of the 2 siphon cures the problem.

If you have a wier type overflow (eg CPR), then using a PH to evacuate air is recommended, as the flow in the wier is too slow to clear bubbles.

There are ways to quieten the overflow. A Durso attachment is one, as is a fully submerged standpipe system, like this:
BeanAnimal's Bar and Grill - Silent and Fail-Safe Overflow System

 

[AMDPhenomX4]

I took a PVC connector with 3 openings, put a hole at the to where the top would be and put the bottom in the overflow pipe. Mine is so quiet i can sleep with it. The noise from the water coming out is louder.

In this pic the hole would be on the bottom. I then stuck a piece of airline tubing out of the box.
This was a modification of the larger designs