Can anyone help with this problem??

I have two tents running both have this equipment:

1.2 x 1.2 x 2.0 Mylar covered tents
600w HPS cooltubes in both
6'' fans one on each cooltube >>inlet>>>fan>>>cooltube>>>outside
4'' filter and rvk fan in each tent both extracting outside
4'' inlet fans on both tents (and partial filters) with fan controller so i can control neg pressure pulling air from outside
oscillating fans in both

temps are low in both tents over the last few days its got cold 7.9 lights off 20.3 lights on, i will be putting my tubler heaters on very soon.

Nutes:
ionic range the hole range but just feeding BLOOM at the rate of 2ml per litre they had boost last week 1m per litre i feed water water feed but only when my pots are light
water PH 6.5 (tap water) run off PH 6.0
soil clover compost good stuff 30% perlite never had a problem with it, 12lt pots.

problem is not bugs look high and low with micro scope.

mainly large fan leafs that are effected.

Tent one: afgan skunk has no problems at all well happy with these doing the same feeding as tent two.

Tent two: exo clone only cheese 3 weeks in to flower pain in the ass plants that have horrible looking leafs this is what i cant diagnose could someone help me with this:

6.0 ph is low,get it to 6.5-6.8

I dont think its a ph problem as I say tent one has the same run off ph and thay are fine its my soil that buffers the 6.0 ph have you tested your run off most soils give you a ph of 6.0 plus with ionic I should have a ph of 6.0

I do value your help though

Any one else any ideas

What im thinking is phosphorus deficiency caused by low lights off temps and this cheese cant handle it like the afgan skunk can on the last run I had no problem with this cheese temp were high then just cant put my finger on it

In my opinion it looks like it could have had nute burn. Did you start your last round of nutes at 1/4 strength? Same thing happened to me recently. I would flush them. I also concur with BigJim that your Ph is too low. I usually bump my PH up to 7.0 with soil.

When in doubt flush and give a low feeding with correct PH, Mon also thought maybe nute burn but too hard to tell.

Looks like a PH issue how do you feel about foliage feeding?

NWO666 said:

In my opinion it looks like it could have had nute burn. Did you start your last round of nutes at 1/4 strength? Same thing happened to me recently. I would flush them. I also concur with BigJim that your Ph is too low. I usually bump my PH up to 7.0 with soil.

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Less than a 1/4 strength mate.

HotShot7414 said:

Looks like a PH issue how do you feel about foliage feeding?

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I dont folia feed never have done but y?

Im still lost all this talk of ph has my head in bits but on a good note ive looked today and thay dont seem to be getting any worse anyone else's care to shear opinions??

is it maybe a tent off gassing problem

Mate I've used Ionic range, PH is fine, nutes seem really low for bloom 2ml..... Recommended 7ml, Do you have a EC reader? ..... Again Ionic bloom EC suggestions is 1.5 I would start on 1.2 and work up over a week or so to 1.5 and even go to 1.8 after a few weeks, if the plant shows any signs of nute burn drop it back down to 1.5 etc... Looked like on one pic that the leaves effected was the top.... If so defo heat stress, lift the light a inch or so.