Well some leaves started to curl in week 2 but now a lot are so I'm worried. The tips are burned and are starting to curl inward as you can see in the pics. Some leaf tips look to have just dropped down, I'm not sure what's happening. I'm thinking it's possibly a calcium deficiency because the Nutes I use Cornucopia Plus contain no calcium in them. When I first started flowering I used part grow solution and part bloom. Today is day 21 of flowering, I haven't changed my reservoir water in the 3 weeks so far. I use a ebb and grow flood and drain bucket system with a reservoir I keep 25 gallons full and run 12 buckets on currently. I was told by my local hydro store that the more gallons in my reservoir the longer I can go without changing my water..so I was thinking I could get about 3 weeks with 25-30 gallons of water. I did add 1/4 cup of bloom nutrient when I started to see leaf tips curling but that hasn't helped. A link to the bloom fertilizer is here: - Ammoniacal Nitrogen = 3.0% - Nitrate Nitrogen = 7.0% - Total Nitrogen = 10% - Phosphate = 10.0% - Potassium = 12% - Magnesium = 1.5% - Sulfur = 1.0% - Manganese = 0.056% - Zinc = 0.05% Derived from: Potassium Nitrate, Potassium Phosphate, Ammonium Nitrate, Magnesium Sulfate, Ferric Citrate, Manganese Sulfate, Boric Acid, Zinc Sulfate, and Barley Extract.Advantage Bloom, 16oz I read that the plants take in a decent amount of calcium almost as much as nitrogen and potassium so I'm thinking my problem lies there which I was thinking about just adding some calmag plus. Other than that I'm running about 650 tds level which is a bit high for this nute line supposedly. I was told 300ppm is normal. Which I had originally had 300ppm when I started but it raised I think because there were a few spots where the light was hitting the water therefore evaporating the water and leaving the salt behind? not sure. But it raised till I covered those spots up and now seems to hold steady at 650ppm. Suggestions, comments please.