My tank is a little over 9 months old at this point with about 35-40 lbs of LR. (40 gal long tank) From the beginning I always had TONS of pods swimming and scooting all over the rock and Crushed Coral bottom. About a month or so ago I switched from CC to a sand only substrate and ever since then the pod population has declined rapidly. I use to see the pods at all hours of the day and my scooter blenny was constantly chasing and eating things. Then about 2 weeks ago I noticed the scooter acting funny, swimming up the sides of the tank and trying to pick at alge or something on the glass (instead of scooting along the bottom as usual) He doesn't seem as nice and fat as he use to anymore, in fact you can see some of the indents around his head that you never use to be able to see. I also don't see any pods during the day and at night I'm lucky if I see 1-2 with a flashlight. I used to be able to shine a flashlight in there at night and see hundreds, literally, swimming all over. Whay has my pod population pretty much gone exstinct? What can I do now?