Dont know what I did wrong...now they're both dead!

Not sure what Organic aqua is. Cycling with Chromis for 6-8 weeks, should do the job.

 

Sounds like you found the right place and i'm glad you didn't give up! Fishkeeping is one of my most satisfying hobbies and i'm sure you will find that as well. It seems you are very conscientious and are very keen on doing the right thing for the fish, not just for appearances. I would like to suggest that if you're going to add those sponge bob houses and stuff that they need to be washed VERY thoroughly. In transport the the local fish store (LFS) they are in contact with a lot of things i wouldn't want in my tank. Also, live rock (LR) and skimmers have also been suggested already - essential for a good start. GL and happy fish keeping!

 

I agree mostly with SoStoudt... Salt isn't what killed them (it is low) but lack of Bacteria could be an cause. Clowns are a Damsel so they are a good starter. 15g is kinda limited. You do need Bacterial matter as in sand and rock to help support life but IMO your problem lies in cycling. Nothing died in the tank yet and it is newly established. Cheap Chromis' would suffice for a month or two to "pee and poop" and they are Hardy enough to live till you can cycle enough for Nemos. Good Luck! and welcome to salt!

 

water

what kind of water did you use and where did you get it from