What's a good cheap and plant friendly cleaner for cleaning airstones and rest of setup? Was thinking dail dish soap or very mild bleach solution but didn't know what affect would have on the stones.
Bleach works well and is cheap....just rinse really well after cleaning. 30% H2O2 is a good, safe alternative but way more expensive.
I keep a 1 gallon bucket of water with about a cup of 29% H2O2 and a teaspoon of Physan20 for storing the tools that are in contact with my nutrients in my reservoirs. I also drop my air stones into the bucket for a few hours to clean them. If they have a lot of stuff on them I rinse and brush off that material first before the soak. This works real well. The H2O2 oxidizes any organic material it contacts. The Physan20 kills any of the single celled organisms that may be left. Physan20 is poisonous to plants at this concentration but the small residual amount left on tools, stones etc is not and quickly dissipates. I also use Physan20 at 1tsp/gal (no H2O2) to clean my systems between crops. It sterilizes the equipment well. Besides, it smells much better than chlorine! I like the peace of mind that KNOWING everything is clean gives me when starting a new crop. I have used this method for several years without a problem. Early on, my hydro experience taught me that keeping everything clean is absolutely necessary.
I use normal household bleach, roughly 50ml in a 3 gallon bucket, soak things for a few hours, then rinse and dry
peroxide is REALLY unstable and won't last long in solution. It will rapidly dumps 02 (hence the bubbling) and leaves you with regular old water, so a bucket of water with a cup of h2o2 is probably just water within a day or two, and doesn't have much oxidation potential prior. the best thing to use would probably be star-san or physan20. both seem to be good sanitizing agents that are food safe. star-san is used extensively in the brewing industry, but i would give everything you clean with it a quick rinse with fresh water to remove any possible salt residue just to be safe. wip up a batch, run it through your system a couple times and keep a jar of extra to dunk any tools you use. could probably keep it in it's own res and use it a few time (it's fairly shelf stable), I dont know much about physan but it sounds like it might be something that you can even use while your plants are still in the system as long as the solution is weak enough, though i don't think i would try that personally. otherwise just seems like a slightly less potent sanitizing agent, probably just what your looking for. if you use bleach make sure you rinse everything VERY well, otherwise you will probably have problems on your next grow.