Thanks for the info. The snail is out of the question pretty much.. puffers + clown loachs haha..
I may get a drop checker, but where can I get one? I'd love to leave my airstone on 24/7 if it wouldent bother the c02. My c02 tube goes into the strainer on my penguin 200 for right now.
BlackSunshine, a member on this forum, sells them. He is a pretty decent guy to deal with and I have had no problems with the drop checkers that I bought from him. He also includes the proper solution to use in the drop checker, so it is a plug and play solution. With the ones you buy elsewhere, you either have to make your own solution which is not difficult but can be a PITA or purchase the solution seperately which can get costy. Anyway here is the link.
Also, with the airstone, just have on on standby in case of an emergency, you may not even need to hook it up. It will be difficult to know your c02 levels without a drop checker unless you sit by your tank 24/7 while the C02 is being injected to see if the fish are spending most of their at the top and appear to be gasping more than usual.
And it is okay to feed your c02 tube through the strainer of your filter. That is what I am doing on a tank I just set up and it appears to be working fine. Just place a check valve and or bubble counter in the c02 tubing to prevent the snot plugs. The snot plugs are not harmful but could clog up your filter with some slime.
In another tank, where I am feeding the c02 tubing to the intake of a filter, but am not using a check valve or bubble counter, I am noticing some pretty wicked slime from the c02 snot on the polywool every week when I clean my filter.