Help with this Excalibur HOB Skimmer

I been wanting to give this skimmer a try and even after giving 3 different pumps a try I can't get it to work, each time I used a larger pump.

I had given up my today I pulled it out and gave it a look over and I think I may know why it's not working. In the posted pics you can see the input part of the skimmer is much smaller than the output part.

The problem I am having is the water in the chamber is not pushing high enough to be effective. So I am looking at the output part. 1st is there a part missing on it? 2nd I am thinking since the output is so much larger than the input that there is not enough back pressure to raise the water level high enough to skim proper.

Any ideas?

 

So does the outflow need to be restricted?

 

Are you sure the input is the smaller one? My Reef octopus hang on's input looks like your larger tube....? I'm sure it's probably completely different......is the smaller tube what you hook your pump to? Is it an intank pump? Mine is outside....

 

What types and sizes of pumps have you tried?

FWIW, I had one of those a few years ago- it worked great with a RIO 800 w/built-in venturi air intake. If the water is making it through the return line and back into the tank, then the level in the chamber has to be correct for proper operation. Sounds like you might not be getting enough air or small enough bubbles; the RIO venturi is a double-pass unit that creates ultra-fine bubbles and IIRC, the 800 is the one specified for the Excaliber.

BTW, once you get it running properly, you will want the bubble trap; IME, the tank water looked like milk in a very short period.

Here's the pump:

Taam Rio RVT (rejuvenating venturi) Powerhead/Pump

 

Yes! the smaller one is the input, that larger to me sure looks like something is missing, and that small hole on the side makes it even stranger.

 

Thanks Mr Bill, That's the 1st pump I tried, that exact one. Then I got a Rio 1400 and the water level in the chamber still was not high enough to skim at all. The Skimmer I am using now has a red flow control knob to control out flow.

 

If the water in the chamber is reaching the same level as the outlet line, then it should work properly if you're getting enough air; the foam is what pushes up to the collection cup. Keep in mind that the Excaliber is old-school technology. Heck, mine looked like a DIY project. But back in the day, it was the shiz because it didn't require an air stone.

What's missing is the bubble trap. It's basically a large box with a big hole in the bottom that you keep covered with a sponge. That mounts to the hanger and sits inside the tank. The hole is an air vent to prevent excess air in the line from back-feeding pressure to the chamber and flooding the cup as the bottom of the pipe is usually submerged. The fact that you're not getting a TON of bubbles in your tank without the trap keeps telling me there's something amiss with the air flow. FWIW, I didn't have a regulator at all on mine...

Could you fire it up and get a good pic of it in operation?