Synergy Reef Shadow v2 Overflow Noisy Internal Box

[keithIHS]

Here's the problem: The water entering the internal box at the weir has to fall too far to the water level in the overflow. It's about 3/4" from the midpoint of the weir openings down to the top of the external box. You really ought to have about 1/2" from the top of the box to the top of your emergency drain (Bean Animal). I tried 1/4", but with a lot of flow you need some headroom for water to overflow the top and there's quite a bit of turbulence and waves. Maybe it would be OK with only 1/4" with the lid snapped on, but see below. Your open channel should probably be at least 1/4" below your emergency. This gives at least 1-1/2" drop which can be noisy. Another complication is that if you use the U pipe at the top of your open channel stand pipe, it's top will be about 2" above the water level, which will put it above the top of the external box and the lid won't go on. If you shorten your open channel stand pipe, you either have to have a lot of flow in your open channel, or the drop increases to about 2-1/2".

 

[Reefahholic]

Hmm, I’ll have to see how mine fits. I had no problem with the previous model. You have to cut your pipes to accommodate the external box with the normal running water level and also tune the system. I’ll report back and let you know if I experience the same issues. Just looking at the design I don’t foresee any issues honestly.

 

[keithIHS]

My emergency is absolutely as high as I dare make it, and the open channel is only a skosh below it. There really isn't any wiggle room there. And yes, I spent a good bit of time tuning it, rather successfully if I may say so myself :). Unfortunately, tuning doesn't affect the water level very much at all. It affects the noise coming from the main and open channels, but not the drop from tank through the weir. The top of the open channel determines the water level in the box which then determines the drop. At higher flow rates, the drop will make noise. I replaced it with ExoticMarine's and now no noise (but fish go through the weir). No noise because the external box is higher so the top of the open channel is higher so less drop so less noise. Very interested to hear others' experiences. If you can, determine the drop from your aquarium into the box and the flow rate, and let us know. My drop was about 1.5" and 450-500 gph, and that gave too much noise.