aero cloning. stems sometimes get soggy

i've been aero cloning for quite some time. i usually have pretty good success but every once in a while i run into problems where my survival rate drops. it seems like the smaller the clone i cut, the higher the survival rate. a lot of my bigger clones, the stem gets all soggy and i have to throw them out. it has been really hot in the room where the machine has been lately. like 85F so i imagine the water is the same at least. could have have something to do with it? are bigger clones just harder to root? i've cloned hundreds of times before it always seems like i have problems from time to time. im using a 13W CFL but i have a 55w t5 i could use instead if that is better. but i always thought low lighting is better for clones. once the clones have a nice root mass and i put them in a cup of pro mix soil it seems to be 99% survival rate after that though. but this last recent batch i cut bigger clones and the stems are getting soggy on a lot of them. then the leaves inside start turning yellow brown in spots and i just throw them out. i could get pics if needed. also what does everyone prefer the water temp at for aero cloning? is it 68-70F just like for hydro? i also use clonex clone solution clone and seedling nutrient. it's 1-.4-1. i only add 1tsp for the entire 2 gallon reservoir. i just use tap water ppms are about 190. i keep ph 5.8-6.2. after adding nutrients and phing my ppms are 240. i tried going a bit high before for cloning solution and i was getting salt buildup and it was hurting the clones.

my guess is too much heat or maybe just bigger clones are harder to do.

any help is appreciated. thanks guys!

yah your cloning solution temps are to high.

ok thanks. guess i will just have to put the system in the room with my ac and set the ac to like 75. what should i keep the water temp at? is it the same for normal hydro? i guess i could put ice packs around get a couple friends to change them for me when im not around several times a day. i actually have a chiller but probably be too much hassle just for a small system. damn i hate these summer grows.

My 2 cents but I had low clone rate too in high temps until I started adding 5drops of bleach to my reservoir every 4 days. I get roots as little as a week on some strains (pineapple express, Blue venom, blue dream) my roots are bright white and by 3rd week roots are at the bottom of the bucket. My reservoir temps reach 84 sometimes.

Bleach has no effect on my ladies. Just kills the bad germs and bacteria.

thanks. i have 29% h202 but i stopped adding it thinking it may have been hurting things. maybe i should add again. i always heard bleach was bad for growing but may be worth a shot. i mean they're just little clones, it's not like they have buds or anything

If resovoir temps r two high try turning you pump on 45min off 15min seems to work for me