Is this phosphorous deficiency?

I'm in about 2 weeks of flowering. This started and seems to be progressing. The water temp was @ 70, ph @ 6.0. I'm doing aquaponics.
I've since bumped up the temp to 75 air temp is at 80+.I added bone meal. But doesn't seem to be slowing down. Most of the leaves turning are at the top but I guess you could say it's all over. Mostly older growth.

Doesn't really look like P deficiency to me. There are usually dark blotches that spread as the leaves go a dark blueish green. Growth gets stunted and slows down too. Stems all start going purple too.

Almost looks more like water damage or some sort of fungal attack rather than a deficiency.

Wish I could nail it down for you but they're odd symptoms.

Good luck.

foliar feed for awhile to protect your fish

Don't Bogart said:

I'm in about 2 weeks of flowering. This started and seems to be progressing. The water temp was @ 70, ph @ 6.0. I'm doing aquaponics.
I've since bumped up the temp to 75 air temp is at 80+.I added bone meal. But doesn't seem to be slowing down. Most of the leaves turning are at the top but I guess you could say it's all over. Mostly older growth.View attachment 3946596View attachment 3946602

Click to expand...

NO! Pic #2 says it's a pH problem and your getting lock outs. Ph to 5.8 and let it rise to 6.2 or so before adjusting it back down. If your pH is dropping and not rising.....You may have a root problem.
Then again, if your using RO water and not buffering it with a Ca/Mg first. You have way low Ca.....You also need to keep the water temp below 70F.

Just added PH+. PH has consistently been at 6 or maybe lower for over 2mos. My PH chart doesn't go below 6. It's for Aquariums.

OldMedUser said:

Stems all start going purple too.

Click to expand...

That is one of the symptoms. Stems are going purplish red.

Most of my plants have red stems. Seems to be their natural state as they are growing fine.

A low pH can cause as many problems as a high one so with any luck it's as simple as that.

Don't Bogart said:

That is one of the symptoms. Stems are going purplish red.

Click to expand...

good chance the 2 aren't related

Don't Bogart said:

Just added PH+. PH has consistently been at 6 or maybe lower for over 2mos. My PH chart doesn't go below 6. It's for Aquariums.

Click to expand...

Mmm.
That "spread" of pH is there on purpose. Some nutrients are better available at lower values and some higher values - like Ca and P.

The "swing" in pH is natural and needed by the plant for an "even" availability of nutrient.. In soil that swing is replicated by the soil dropping in pH after watering, and then rising back by drying out.

Now if it just sits in one spot and does not move.....Looks like the plant is expressing that. You might try adding a Ca/Mg at this point.
It should not hurt the fish......I have no real idea about how to make a fish based aquaponic system "swing" in pH.....

The Tilapia based systems I've seen. Always had problems with lower N.....I figured it was the effect of fish to available water being cycled....

Anyway, let me give you a Phone number to someone who runs aquaponics all the time. He has a pretty good sized system in his shop set for veggies (real one is at home)..

I see you'll have to PM me for that TX number. Drop me a line and I have that for you.

Dr. Who said:

Anyway, let me give you a Phone number to someone who runs aquaponics all the time. He has a pretty good sized system in his shop set for veggies (real one is at home)..

Click to expand...

Funny you should offer that. I just found someone local. I've been in contact and they're stopping by.

Looks like magnesium dificiency

Folliar with mag pro

I beg to differ. That is not low Mg. It starts with interveinal chlorosis that would show on all the fingers of older fan leaves and not brown spots on a couple of fingers. I still think it's just some light fungal infection as it's not consistent with the same types of leaves like most deficiencies.

Hope you friend sorts this out for you, if you are in doubt please post more pic's , I need more input to help you better

Don't Bogart said:

Funny you should offer that. I just found someone local. I've been in contact and they're stopping by.

Click to expand...

GOOD DEAL!

Still, if you need more.

So Doc, you called it. PH blues, (or is it red??). So it's been a struggle to find the proper stuff to try and control it. I did water changes over a few days and was able to get it up to 6.4. My water out of the tap is about 7.2.
I knew this wouldn't last and sure enough it started dropping about .2 a day.I was able to find hydrated lime locally. 50lbs.
One tps. brought it up from 5.9 to 6.1.-6.2.
My whole flow is about 55 gal.
I'll let that sit there until tomorrow. I've also ordered potassium hydroxide. Should have that by the end of this week. Will mix them 50/50 and add as a stabilizer as needed.
I now have a meter. Bought a Hanna. I just also ordered the neutralizer and calibration solutions from them. It came with little packets but that won't last long.
Plants took a beating. But as I said to my wife. I'll chock this up to experience. The next time will have DIFFERENT problems, but not these.

I would have also suspected magnesium def

but the two pics show differently

the pic of the plant looks to be magnesium def to me

the leaf margins are curling up on the edges of some leaves
I would add 1/4 tsp Epsom salt per gallon to your feeds (if that's safe for your other biology) and or foliar feed 1/4 tsp per gallon

if im wrong theres nothing to loose adding the epsom salt .. the extra mag wont do any harm

the pics of the leaves alone looks different to me possibly showing high N but that could be a picture thing im not sure
but looking at the two pics I wouldn't guess theyre form the same plant cuz one pic looks lighter green and the other very dark

im interested to know how you will supplement magnesium organically for aquaponics

ive never done it so im not sure what sources of magnesium you have available that are fast acting and can be added to your other biology
not sure if Epsom salt is safe or not for fish or whatever

or will you add lime? and if so how long will it take to become available

Folliar feed

Dynamo626 said:

Folliar feed

Click to expand...

that will help his short term needs but what would be the long term plan for adding magnesium to the root zone

as ive never grown in aquaponics im not sure what the available/safe magnesium sources there are or at what levels they might be to protect the entire environment

im sure theres an answer and im curious to find out...maybe theres an exceptable level of magnesium sulfate that could be added without causing the fish to have excess laxative lol ...joke

or maybe its more delicate and would require magnesium sources thru something more like kelp meal or some unrefined mineral source