where can I find epsom salt?

How many shells should I use for 2 litres of water?

Epsom salts can be bought at any supermarket or big box type store....or pharmacy. Look in the first aid area, if not there it could be in the bath/body section. As for the shells, I usually do a dozen for a 3 gallon pot, you really cant over do it so don't worry, you are basically extracting a bit of calcium from the eggs is all. Boil them for about 20 minutes then strain and cool.

this is just a question, but couldnt you use some antacid tablets? all it is is calcium bicarbonate. is that the correct type of calcium you are looking for or some other type of calcium?

the other route would be to go to a hydroponics store and ask the workers there for the micronutrients or calcium and phosphorus.

lower your ph to 6 - 6.2 for soil ... lower humidity during flower to 30 - 40 %. I would use a sugar additive during flower as well, I use molasses. Its normal for plants not to be able to hold themselves up .. personally i tie up the cola, and use x mas hooks to hold up branches, hook branch to main stem .. on a 6 plus footer you will need to tie to ceiling, walls will hurt growth ..