catchandrelease

Also if you have an HOB filter make sure your water is topped up to avoid too much surface agitation, when your using diy co2 every last bit needs to be utilized.

There are varied opinions on how co2 is more easily utilized. Personally i prefer to have it diffused 100% into the water, where as many people feel that it is more beneficial to use the powerhead impeller to create a co2 mist throughout the tank. Reasoning behind that being co2 bubbles will sit under plant leaves readily available for use. Like i said previously an inline reactor is the way to go IMO but if you dont have a canister filter a powerhead is the next best thing. Option 1 being to put the co2 outlet in a place where the intake for the powerhead will suck in the co2 and the impeller will create a mist and spray it throughout the tank. Option two being http://www.plantedtank.net/articles/DIY-CO2-Reactor/2/

I have 11 rummynose and they are amazing fish, i would be suprised if they stopped schooling in a 55g even without any predetory presence. They havent stopped schooling in my planted tank, and i wouldnt consider cherry shrimp to be intimidating to a rummy. Plus they look great.

BTW diffusion bells are not your most efficient option for diffusion. there are many better options, if you are willing to buy a cheap powerhead i can send you a link to a diy you can do that will give you near 100% efficiency, I run an inline reactor with pressurized now but prior to that i had the red sea 500 reactor, worked quite well with DIY co2.

That fuzzy stuff you see is a inevitable byproduct of diy co2. What you can do to stop that is make your self a bubble counter with a pop bottle, drill two holes in top and run the tube from the co2 bottle to the bottom of the bottle. The get another tube a just put in about 3/4" past the lid (this one runs to the airstone). Then fill the bottle with wwater to about half way. Then the co2 gasas will bubble through the water in the bottle and come into the other tube and go into the tank. voila, no more fuzzy stuff