Hi,
DSB crashing? It is a possibility and it could happen. When cyano and dino grow on the sandbed, it is commonly believed that the DSB is dead underneath the cyano.
I agree with Steve's Theory and it does make sense
Chemi-clean would probably work, but I would use it with caution and monitor the tank carefully (i.e. skimmer flooding). The only problem is that we won't understand the root cause of the problem.
- Victor.