if there is alot of plant matter above it, the reason could be that they are dying because no light is getting to them, if it is in this case, you dont have a thing to worry about
I'm using 15-30-15 fertilizer with micronutrients i give it fert every sunday and i water once or twice a week whenever it needs it. we have been having bad weather like rain everyday for last week and a half so i havent watered it or gave it fertilizer since the weather change.
As long as your medium is mixed light enough to where you have no standing water, this can't be a problem. I'd recommend top dressing some cow manure or some sort of guano since you're having tons of rain. This will give your plants a jump start and they'll turn a nice lime green color!
I just went and bought some Laters Bloom Booster 0-12-12, is this all i should use for fertilizer during flowering? It says to mix 15ML with 4L of water is that to strong for the first time?
mix it at 1/4 next time a little more. then watch and adjust as needed. I don't know anything about your nutes so can't say for sure but 1/4 mix is usually a safe way to start new nutes. Mine is a 0-10-10. and don't have any problems at the full mix. You could also add blackstrap molasses and super thrive if you wanted. thats what I use most of the time.