Need Advice about pH

If this is too long to read I just need an answer to this question: How much vinegar should I add to a gallon of 7.3 pH RO water along with my very small amount of nutes to get it to a 5.5-6 range? The pH of full strenth nutes (i'm using 50%) is 6.08 according to Technaflora. I used a dash, about 1/32 of a tsp last time. Until my pH meter and pH down get here this is all I can do. I'm fully aware vinegar is not good for Phing, and I'm fully aware I need a pH meter with coco, but right now I need information, not poor-shaming.

I'm using Technaflora nutrients in coco coir with Auto AK under a 400w HPS, feeding full strength every watering, (between 40% and 50% of prescribed levels) and up until this point everything has been amazing except for slight N.tox when switching to flowering. I now believe that previous N. tox was just the beginning of my nute lockout taking place. I used RO water + nutes for the first few weeks, and then i took some anecdotal advice and started using my tap without pHing it. All was well until a few days ago when i noticed severe N. tox, calcium deficiency, and what just looked like general nute lockout. There's yellowing leaves on the bottom, leaf clawing on the top, yellow spots on some top fan leaves, necrosis and brown spots on some of the dying leaves. They're about two weeks into flower. So here's where I really screwed up, i bought a cheap 3-in-1 pH meter and went by those horribly inaccurate results and flushed with tap water.

I then came to find out that the pH meter was completely inaccurate, fluctuating readings between 3 and 7 for the same water, and displaying tap water with a tablespoon of baking soda as more acidic than normal tap. So i smashed that pH meter and I have a new one coming in like 10 days, but until then I accidentally flushed with a tap water that has 8.6ph. I didn't mistype that, i did in fact mean 8.6 pH. So until now the only thing keeping my plants alive has been the fact that the nutes have been lowering the pH enough to create a semi-livable environment. I flushed them with reverse osmisis water with a small amount of nutes and about 1/8 of 1/8 of a tsp of vinegar per gallon less than 30 minutes after this horrible mistake, and they haven't gotten worse.

Should I keep using about 1/32 of a tsp of vinegar to water until my supplies get here? If not, should I use less or more? I'll have some pictures up of the leaves after I make lunch.

Its going to depend on the pH of the brand of vinegar you have.

Oh crap good point. Says distilled with water to 5% acidity, so 2.4pH. There has to be a way to math this out but I don't know it lol.

7.3 starting pH of one gallon of water. How much of a 2.4pH solution is needed to bring that water to 5.5-6 is the updated question I suppose.

Why not create a test scenario with a fraction of your mix against a small amount of vinegar, then when you get it right, multiply up to the amount you need for feeding?

-spek

For instance, when I need to pH down, I use lemon juice. I have two 2.5 gallon auto-drip reservoirs for feed, but I don't test in those.

I test against a 1/2 gallon (2 litres) of mixed water and pH that. Once I get the calculation right for each res, I multiply that to what I need, then create large batches.

-spek

spek9 said:

For instance, when I need to pH down, I use lemon juice. I have two 2.5 gallon auto-drip reservoirs for feed, but I don't test in those.

I test against a 1/2 gallon (2 litres) of mixed water and pH that. Once I get the calculation right for each res, I multiply that to what I need, then create large batches.

-spek

Click to expand...

Well I currently don't have a pH meter. One is coming. I did find out that 1ml of white vinegar will bring water down around 0.3 pH depending on its beginning alkalinity, so I'll probably just add that per gallon for my feeds until it gets here.

I completely overlooked the fact that your pH meter doesn't work. I apologize. Perhaps you can at least pick up some of the paper strips until you can get a new meter.

Good luck.

-spek

I'll look for some today. Another question, so the yellowing of leaves has stopped and I didn't have to pick any leaves off today, and no new leaves are yellowing/having symptoms. I'm getting some yellow spotting on top of the plant that looks like calcium deficiency or ph swing stress. Is this most likely just because i flushed down from that hellish pH to a reasonable one? Can flushing OUT of a stressful pH cause pH stress if you do it too fast? Either way my growth seems to be continuing and nothing is getting worse.

I still have leaf clawing, but I'm not sure if that's supposed to get better this quickly, and I've been feeding 1/2 strength or less.