[MarkS]

Originally posted by H20ENG
Mark,
I built a nano tank with a built in RCSD, and I used a 3/4" vent. I'll use 1" next time.

I remember the original SeaScope article talking about the need for a huge vent, and how he kept increasing the size, all the way to 4".

You need to get the pressure out of the box ASAP. This way the water can rush in as fast as possible. But, if you only have a small inlet, you wont move the water very fast, and consequently, wont get a great surge. So for your setup I would either slot the tank or put at least 3" plumbing and a minimum 2" vent.

Another way to get a stronger surge is to mount the RCSD lower in the tank. This way there is more head pressure on the water trying to get into the box. You will need a stronger air pump for this though.

You could also run the vent plumbing out the top of the box and over to the tank. This would eliminate a nother plumbing line in the display. Just make a U inside the RCSD box.

HTH

All good ideas. I might as well go to a 4" outlet with a 2" vent. I'd love to slot the tank but how would I seal the surge tank to the main tank? Bulkheads are easy.