Help me get through flower, killed one plant already.... cal def? +rep 4 help

So i killed one of my two plants somehow when switching to flower cycle. that sucks, but at least one lived. The plant in the pictures is my survivor. The leaves are all light colored (lighter than pics) with some light spotting of yellow. Some of the small leaves have dried out and gone chrispy. Most of the older bigger leaves just look like they need help, but are not chrispy.

Specs of grow; i use GH 3 part flora series. Light is a 400w hps, supplimented with a few cfls. Growroom is decently ventilated(could be better) grow box is the same, i am 2 weeks into flower at this point. Water is always distilled. PPM for res is 1000-1100. Ph sits at 5.6-5.8. I ocassionally put in a hunk of dry ice to help boost the co2 a little.

here are some pics to somewhat show what im worried about. Thanks for the help

1000-1100 is too hot in my opinion if you are just using distilled...full strength fox farm in distilled is only like 7-800 ppm.I'd flush for a day with ph distilled and maybe 200 ppm nutes, then come back with 600ppm and see how that goes.

Are you sure about the ppm? most say low 1k is okay during flowering. usually i keep it at about 900 but when the water gets evapped out the ppm slowly rises.

yeah I know the FF feeding schedule says the same thing (like over 1200ppm), but I've got a hanna meter and it's properly calibrated and when I dose fully it's like 7-800 ppm when using distilled. My plants were getting sick at 1000-1100 too.

If you are using the proper amount of nutes (x tsp per gallon or whatever) and you are getting that ppm, that's one thing. In any case if 900ppm is a full dose, then you have to be sure it isn't getting above that...

In any case, listening to what just anyone said got me in trouble and I ended up using too much nutes, so you are right to be skeptical. But I don't think lightening up on the nutes could hurt anything...surely you don't think it is a deficiency? your ph is fine so it's not that...only thing left is heat stress / light burn /pests / root problems, but I think you'd agree it's none of those...

good luck.

Thanks for the added info.. When your plants were getting ill did they show as mine do? I generally use the bottle reccomendations but a little light. I have a 12 gal res but i usually nute for 10gal as at one point i did get some nute burn. At full strength i believe i was at the 1150 range with my hanna, which scared me pretty well.

as for deficiency i was told to consider a mag or cal deficiency as it is rumored to be common with GH 3parts.

"Magnesium: Lower leaves turn yellow along the tips and margin and between the veins; the lower leaves wilt...

Calcium: Young stems and new leaves die..."

taken from the guide to diagnosing plant problems. This appears to be what is happening to my plant, young stems and leaves fry/wilt fast and i get yellow tips and between the veins.

roots look fine and i had some sort of bug(maybe spider mites) but i, think, took care of them. Lights are good enough away dont think they are burning. Heat could be an issue, i havent a thermometer but during the day it tends to get a bit hot inside(high 90s outside temp, ugh). I will have to look more into that as well.

Thanks for the input

here are links to the problem I had
https://www.rollitup.org/marijuana-plant-problems/337221-ph-problems-need-advice-pics.html
https://www.rollitup.org/marijuana-plant-problems/339608-yellow-spots-other-questions-just.html
https://www.rollitup.org/marijuana-plant-problems/340916-tried-many-things-need-get.html

if you read through them all, you will notice I thought it was mag / cal too... But the more stuff I added the worse it got. I did have the little yellow spots like you have, but not sure if I got any good pictures of them.

What finally solved the problem was getting the nutes and ph just right.

I don't know a lot about GH 3parts, but I would imagine most nute regimens would have pretty much what you'd need to grow, certainly they wouldn't be lacking enough that it would actually kill your plant.

If you are sure it is cal mag you may be right, but just be very careful. What I would do is pick a leaf and take a pic of it once or twice a day once you start adding cal mag, if it gets any worse at all, then cal mag is not your problem.

compared to FF GH has more calcium but less mag, so if you wanted to try just mag, then you could try a little epsom salts.

but if you look through the pics I posted, I think my problem looked a lot like cal mag, and I can tell you adding cal and mag only made it worse once I got my ppm and and ph well under control and started adjusting it daily, I had a big improvement. Right now the plant looks awesome, it's 3ft by 3ft and 4ft tall.

if you could get some better pics (not under hps) that would help, I thought I saw browning on some of the tips...is that not the case?

In flowering ) i use soil) I start week 1 with a ppm of 800, and slowly ramp it up to 1400 ppm by week 4 and week seven i slowly bring it down to 1100 ppm and flush last 2 weeks.

here are a few yellow spot pics

Thanks a lot for the advice! i will do some reading through your posts and try to get a better picture

Were your very small immature leafs wilting? mine are which leads me to think Cal, but again im new and somewhat guessing.

The plant that died i think was another non related cause(my bad) and im pretty sure i know what did it.

THanks again for all the help/advice +rep for you

yeah that's the one big difference.. my problem only affected the older leaves (at least 2 nodes down from the growing shoot), and you are right that could be calcium, but you want to be sure you are noticing the weak stems before you decide. Good luck!

I use Gh 3 part nutes and found that you cant switch to flowering and ripening untill at least week 4. Use only transition to flower for first month.My opinion is that the nitrogen in the flowering mix is too weak to keep up the green. Next time in flower use more flora grow. It took my a while to figure it out but as soon as you go to 1-2-3 flowering mix the yellowing takes over.I am no veterian or botinist but I learn as I gf course I grow dirt but the nute mix should still apply. PS amazon.com very cheap place for nutes i get it by the gallon for$15