Nutrient/Ph problems during flowering.

[FONT=Arial, Helvetica, sans-serif]Hello all. New to the community here, and curious to see if you guys can help me out with some problems I've been having. This is an outdoor garden in a greenhouse with soil. I've been foliar feeding with epsom salt 1tsp-tblsp per gallon with fulvic acid once or twice a week. It seemed to be helping for a while, but things have taken a turn for the worst again. I know we have hard water here, and that's been a big problem all year. I just thought I had it under control by adding citric acid to adjust Ph, but apparently not. Nights are getting cold, but we will keep temps above 50 with a heater and some fans. Just getting power set up. I usually give them a ACT once a week or so, and will continue to do so, but some of my ACT may have gone anaerobic which is killing the sickest looking plant. I plan on feeding some Rhizotonic to everything and using a good ACT once again. I'm also going to spray everything with some Serenade here soon as we have problems with mildew right at the end.


Any help or recommendations will be much appreciated!

SOIL:


How long has this problem been going on?

About a week or two

What STRAIN are you growing?

Cherry pie, Chem 91, Ak47, Durban Poison.

What was the establishing technique? (seed or clone?)

Clone for everything but the AK

What is the age of your plants?

5 months

How long have they been in the soil mixture they are in now?

3 months

Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before?

No, they were in Fox Farms Ocean Floor

How Tall are the plants?

4-6ft

What PHASE (seedling, vegetative or flower) are the plants in?

Flower

What Technique are you using? (SOG, SCROG etc)

SCROG

What size pots are you using? (Include how many subjects to pot)

Rows in ground 2&1/2 ft deep, 3x3ft per plant.

What substrate/medium are you using? What
brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)

Tough question to answer, got a canna soil mix from a local distributor.

What brand Nutrient's are you using?

Down to earth.

How much of each nutrient are you using with how much water?

*Knowing the brand is very helpful*

How often are you feeding?

Once a month side dressing, if any.

If flowering, when did you switch over to using Bloom nutrients?

About 3 1/2 weeks ago.
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
N/A

How often are you testing pH/ppm/EC/TDS?

Every time.

What method of pH test was administered? Using Strips? pH pen?

Small vial and drops

How often are you watering?

About once a week

When was your last feeding and how often are you feeding?

A few weeks ago, once a month.

What is the Day/Night Temp? (Include fluctuation range)

Daytime 70-upper 80s Night is anywhere from low 30s to mid 50s

What is the current Air Flow? (cfm etc.)

Is the grow substrate constantly wet or moist?

Moist

Is your water HARD or SOFT?

Hard

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?

Well


If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives?(Only if you have a tds pen)

200

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[FONT=Arial, Helvetica, sans-serif][FONT=Arial, Helvetica, sans-serif]Are you using water from a water softener?

No

Has plant been recently pruned, cloned or pinched?

Pruned about a week ago.


Have any pest chemicals been used? If so what and when?

Azamax 2 months ago.

Are plant's infected with pest's?

No
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Your MgS mix is mixed WAY too strong, imo.

Too much Mg will cause all kinds of problems.
For starters, it will cause compaction quick like.
This compaction will disallow water & air into your substrate & will also lock up other nutrients as well as cause a soil pH imbalance.

Also, if your water is hard, you could be suffering the ill effects of bicarbonates locking up your nutes.

Should I just give 'em a good flush with Ph'd water then some ACT then?

I would stop foliar feeding, go back to the basics and do maybe 1/4 strength flush, I realize these plants are in the ground so you may not be able to flush like you normally would in a container. if you had a reading of runoff ph & ec I'm sure you would be able to fix this quickly, but since you are stuck in the ground that's not really a possibility.

Do you have access to a shotgun/soil ph tester, you could use that to see where your ph is and then correct accordingly.

You could do a slurry test to get ec & ph but I don't know how accurate they are.

No I don't have a ph tester. One plant is completely dying from what I think was leftover ACT in the end of the hose that went anaerobic. Going to try a root drench with neem. I've been battling these ph problems all year, but at least the rest of them are looking like they'll survive.