Curling leaf tips

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.

how hot is your grow room? do you keep the rez. temp pretty cool or does it get hot? anyways about your rez. you should change it every 2 weeks. every week is better but with that size 2 weeks max. did you lift the pots out of the buckets to check the roots? how do they look? you do have a tds meter or is that a guess?? its true that lack of calcium hurt the plant but ive never seen it make plant tip leaves curl down like that. what usually happens is you get brown spots that dry up and crust away and the tips of the leaves get a very little bit yellowed or burnt, and while in flowering it can cause the plants stalk to be very flimsy. i honestly think there is a root issue going on. oh btw what is your pH???

Thanks for the reply. My ph is 6.2 I think... I'll double check when I get home. I was looking at a chart of nutrient availibilities in relation to Ph and noticed that calcium is only available for 5.0-5.8 for hydroponics. I've lifted the inner buckets to check for roots coming out of the small holes and haven't seen any yet. I'm thinking I should lower my ph to 5.6ish and not add any calcium yet to see if that helps? The room is 73 at night, 78 during day..the rez is outside of boxed off room and is a bit cooler like 73 probably. I actually have a digital tds pen tool. Maybe I'll try to check out my roots a bit more. Anything certain I should look for? Browning or burnt tips or what? Thanks dude.

5.8-6.3 is fine for veg but your too high cause in flowering, it should be around 5.3. are you using tap water? if you are you dont need to add any calcium. you only need calmag if you are using RO water, or if your city tap water has a low ppm to start with. i honestly think you got some root issues going on. your roots should be poking out of the holes by now. check out my grow log, my plants in those pics all have roots poking out about an inch and they are smaller than yours. also if your room temps are like that more than likely your rez temps will be high. that big of a rez will take time to cool down from getting heated up from 78 degrees. check your temps around 7pm tonight.

http://boards.cannabis.com/grow-log/...dy-purple.html

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Originally Posted by cigarettes42

http://boards.cannabis.com/grow-log/...dy-purple.html

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Heat problem is little more under control now. we'll see what new temps are tomorrow made a few changes. I have 1 or two very small roots coming out of a couple holes. they're not very big though really strangly. I flood my system every six hours, is that enough for flowering or how often should it be?

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Originally Posted by wakkaa

Heat problem is little more under control now. we'll see what new temps are tomorrow made a few changes. I have 1 or two very small roots coming out of a couple holes. they're not very big though really strangly. I flood my system every six hours, is that enough for flowering or how often should it be?

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irragation cycles varies. depends on temp/humidity and plant, and so on. my veg room runs quiet hot so i flood more often than you.

Wanted to ask you a question about flowering since you use the same system as me. I didn't fore think very well in respect to harvest times. I have several plants all from the same mother but at different weeks entirely in flowering. My question is what would be your solution to the final week in terms of nutrient flushing, aka final flush from advanced nutrients? I couldn't add this to my reservoir because it would mess up my plants in week 3 or 4. I was thinking about putting the plants in a different system all together..my options at the moment are limited to a water culture system. I was also wondering If switching the plants say 3 days before harvest to a completely other system and then adding final flush to the water culture system would damage the final harvest in anyway?
Thanks for taking the time to answer some of my questions, You've been generous and very helpful!