any advice on my problems or setup in general....pics

the big plant is from my first grow in soil(i use bagseed and it was a really good plant)....it did really well with the transplant an then all this happened......im trying to figure out what the white film on the leaves is....its also in the hydroton......i think its calcium or lime from my tap water.....theres also a film at the water levels as it went down and in around where water is used....i designed the whole setup around a bunch of aquarium stuff i had around....the it holds about 27 gallons of water....im using about 100 ml of foxfarm hydro grow and about 75 ml of foxfarm bloom per gallon after i started seeing the burn....before it was the recommended dose on their chart...2 tsp grow and 1 tbsp bloom per gallon on the big plant ...my ph stays around 5.8 to 6.....im looking for any advice at all with the plant problems and how to make my system better or anything else you see that you wanna comment on....all advice is much appreciated....