pH down solution drastically elevates PPM, is it normal?

[Chefbjy]

Very nice...it's a good thing you have nuetral water or it probably wouldn't work. It wasn't 4.9 after dilution was it? It's good to let ph fluctuate a bit between 6-7, and as long as run off is consistent all you have to worry about is ec. Make notes of your mixes and the ph so you eliminate any guess work and it will become natural to you without having to test inflow all the time. Glad it worked for you and good luck 😉.

[MrGreenGenes]

Chefbjy I did it without adding any pH down. I made my Nutrient mix for flower phase (per gallon):

Mammoth P 1.5mg
Humboldts Secret Golden Tree 1.5mg
Humboldts Secret Base A 3.5mg, B 4.5mg
This tap water mixture is 1,440 PPM, pH 4.5

I then split this into two half gallons and re-added water back to full 50% diluted. So now I have two full gallons of nutrient mix 720 PPM. Perfect. The pH of this mixture is 4.5.

After watering, the pH runoff measured 6.9 ( it went up 2.4) and now my soil pH is around 6.9 to 7 and PPM runoff came out a little higher at 860 PPM. Increase of 140.

Next watering per @ campesino suggestion, nutrient levels will be slightly higher. I'd like to finish off around 900-950 PPM.
Lets hope I can even get to harvest.

[MrGreenGenes]

My TDS calibration solution is Nacl 1000 made by HM.

[Chefbjy]

As long as it's in between 6-7 run off they all will be available to the plant. I wouldn't worry about lowering it imho.

[MrGreenGenes]

I just looked up info, My base A B nutrients already have Cal Mag included. (Humbodlts Secret A,B with Golden Tree and Mammoth P). I cant wait to try this modified mix. It would be great if I didn't have to pH down....BUT, we have to hit those magic numbers (pH 6.7 in the soil) for all these nutrients, enzymes and microbes to uptake.

[Chefbjy]

Calmag is a good supplement to use. You don't necessarily have to use it but it won't hurt and airways good to have incase it runs into a cal or mag deficiency. Ph the triple or quadruple recipe. Use another gallon to dilute and see what ph is after dilution. I bet you won't have to use ph down.

[Chefbjy]

Usually feed charts are very high ppm levels if you follow the recipes. And my nutes drop ph. It would be best to ph the nutrient solution before adding ph down. I would be happy with 6.7 and wouldn't try to lower it. But yes you can help it fluctuate by using it on no feed days.

[MrGreenGenes]

I've never given them silicia or calmag, should I be?
I Just watered with nutrients yesterday. My nutrient mix (Humbodlts Secret A,B + Golden Tree, Mammoth P). This mix at my current ratio reads 358 PPM. In theory, doubling these ingredients as you suggest, I should have PPM around 700ish. But Ive never measured just the pH of just the nutrients mix prior to watering. Next time I will for a pre/post reading. And even if I triple the amount of nutrients (High PPM's) diluting down this mix in another container allows for proper PPM's. Smart!

[MrGreenGenes]

On day 30 of flower. I'm in soil. I always add nutrients directly into my water. I'm not using any additional CalMag. My NPK base nutrients are 5-4-4. You mentioned your PPM dropped 400 by letting it rest. How long of a rest?

[MrGreenGenes]

Chefbjy then how will my pH get lowered? I would think manufactures create these juices on the lower side of the pH scale. I'm going to try this for my next watering. I will not add any pH down and Ill double nutrients in recipe (putting me up to 705 PPM / without pH down being added). Very curious to see the EC and pH readings. Soil runoff pH needs to be around 6.5 to 6.9. If I cant get my pH low enough this will generate many other issues. And as you mentioned. Maybe I only use pH down for the non-nutrient watering days.

[FlyingDutchPaddy]

MrGreenGenes, dont think it was asked or mentioned somewhere, but can I ask to which standard your ppm meter is calibrated to?

my ppm pen meter is calibrated to NaCl for example ; 500ppm = 1.0 EC

[Chefbjy]

As long as ph is between 6-7 I wouldn't use it. See what your ph is when you double your recipe. Depending on how many gallons you need you could use a solution like I described below. Maybe even triple or quadruple the recipe depending how many gallons you use. Pouring 2qts into another jug and diluting may save you from using ph buffers at all. And some nutes are good for a week or so premixed in water.

[MrGreenGenes]

Chefbjy my pH runoff is fine, its around 6.7. The issue is the PPM's.
I've been reading multiple forums that say DO NOT include pH when calculating your TOTAL PPM. Measure your nutrient recipe mixture before adjusting any pH modifier as this will greatly effect your results.

Explanation: add all your various nutrients (in the proper order) to your plain water and take a PPM measurement. Then measure the PPM of your plain water. Add them together and this is your TOTAL PPM.

My example Nutrient Recipe:
Tap Water: 45 PPM
Nutrient(s) Mix: 358 PPM
Total PPM: 403 PPM

My Goal for week 3 flowering is 800 PPM. So I should add 397 more PPM's of Nutrients to hit goal.
If what I'm saying is inaccurate please let me know, I've been beat up on this grow...

[MrGreenGenes]

ok, so... I've been reading multiple forums that say DO NOT include pH when calculating your TOTAL PPM. Measure you nutrient recipe mixture before adjusting any pH as this will greatly effect your results.

Explanation: add all your various nutrients (in the proper order) to your plain water the note measurement. Then measure PPM of your plain water. Add them together and this is your TOTAL PPM.

My example Nutrient Recipe:
Tap Water: 45 PPM
Nutrient Mix: 358
Total PPM: 403 PPM

My Goal for week 3 flowering is 800.
So I need to add 397 more PPM of Nutrients to hit goal.

[MrGreenGenes]

I only own pH Down.