Nanocube water level issue -- pls help

[Nanodude]

The chamber #3 (where the pump is housed) is suddenly staying at a low level -- to the point that it's making me nervous about the heater in there. I have cleaned both sponges in Chambers one and two. When I top off the 3rd chamber with RO water, the main tank just overfills, and the chamber 3 drops down again. Anyone have some ideas on how to fix this??

[IxLr8]

I'm assuming that your prefilter sponge is in chamber 1 and your chemical/bio filter is in chamber 2. Chamber 2 shouldn't be restricted since the materials for bio and chemical should flow water easily through them and it would take a lot to get them clogged.

I suspect that your pre-filter sponge is the issue. You can test this by taking your prefilter sponge out while the system is running and seeing if your water levels equalize in chambers 2 & 3. If it does, you've found your problem.

[Nanodude]

Thanks IxLr8.....that's exactly what the problem was. I thought there was only one sponge in chamber one (and clean it monthly). But there is a second one under it that was dirty and slowing the flow! Problem solved.....