Ph down and phosphorus levels

I made a post a few months back asking for help with a plant issue i have been plagued with for years. I received many helpful suggestions from users and adapted my grow to those suggestions. However my issue doesn't seem to be resolved. Basic info: coco, autowatered 4x daily, drain to waste, cocofocannabis GH nute schedule, 350w draw LED, 2x4 space, temperature and humidity control. Without getting too far into it, I have a basic question:

I am using approximately 5ml/gallon PH Down in order to get down to 6.0 from base. This is apparently 5-10x what most people use for the same adjustment. It occurred to me today that PH down is made from phosphoric acid. Is it possible that I am adding enough ph down that I could my plants could be experiencing toxicity? The issues certainly appear similar to what I see online when searching for phosphorus toxicity. I suppose a follow-up question would be:

Using GH flora it seems that the only way to meaningfully reduce P levels is to reduce the amount of "micro". Is this a problem? Are there other things in the micro that I would be missing if I reduce the levels drastically?

I have just tested to see if the ph down is actually raising my tds readings. It is raising the solution by nearly 80ppm! I am mostly just curious if this is something that others have dealt with. is anyone out there using this much ph down? do you have to reduce the P in your setup?

I think it is worth mentioning that I just picked up a cheapy RO system and plan to start using it. I imagine that is going to reduce my ph down requirements dramatically, and if my problem is magically solved i will have my answer.

EDIT: tested TDS affect from addition of ph down only.

5ml,per gal?! What kinda watered down. pH adjuster are you using???? When I add silica, my pH goes to 7.5 and 5ml in 15gal lowers it to 5.8. Something's up here.....
What are you using to measure the pH?
Ro isn't your answer. In fact it will probably complicate things tenfold.

I only had issues trying to follow cocoforcannabis I mean its a good place to start when new to this. When I came here people said ya no remove the calmag stop worrying so much what a chart says let alone a customized one that one grower made..

But I seen people yield pounds with it. Anyways what Im gettin at is whats the EC? Would have to be really high for ph up or down not to work as good but coco for canna guy usually dont pass 1.5ec if that.

I do 1.7ec though one day suddenly and the only thing that changed is I went 3 gallon to 1 gallon pot not even full. I dont even check my ph anymore like its promix lol because lucky me 1.2 ec of maxibloom and .5ec tap water make a perfect 5.8 ish on the test drop kit.

Its a real thing I guess, a coincidental sweet spot that I can take advantage of. Not no 5ml a gallon ph up/down though maybe 5ml for a 55 gallon reservoir. I notice bacteria blooms spike ph out of range alkaline and harder to get back down. I just use 5 gallon buckets as reservoirs now, thats another story.

medidedicated said:

I only had issues trying to follow cocoforcannabis I mean its a good place to start when new to this. When I came here people said ya no remove the calmag stop worrying so much what a chart says let alone a customized one that one grower made..

But I seen people yield pounds with it. Anyways what Im gettin at is whats the EC? Would have to be really high for ph up or down not to work as good but coco for canna guy usually dont pass 1.5ec if that.

I do 1.7ec though one day suddenly and the only thing that changed is I went 3 gallon to 1 gallon pot not even full. I dont even check my ph anymore like its promix lol because lucky me 1.2 ec of maxibloom and .5ec tap water make a perfect 5.8 ish on the test drop kit.

Its a real thing I guess, a coincidental sweet spot that I can take advantage of. Not no 5ml a gallon ph up/down though maybe 5ml for a 55 gallon reservoir. I notice bacteria blooms spike ph out of range alkaline and harder to get back down. I just use 5 gallon buckets as reservoirs now, thats another story.

Click to expand...

Your tap ph can change seasonally, that's why it's best to check every once in a while

Jjgrow420 said:

5ml,per gal?! What kinda watered down. pH adjuster are you using???? When I add silica, my pH goes to 7.5 and 5ml in 15gal lowers it to 5.8. Something's up here.....
What are you using to measure the pH?
Ro isn't your answer. In fact it will probably complicate things tenfold.

Click to expand...

I use general hydroponics ph down and measure using litmus strips

medidedicated said:

I only had issues trying to follow cocoforcannabis I mean its a good place to start when new to this. When I came here people said ya no remove the calmag stop worrying so much what a chart says let alone a customized one that one grower made..

But I seen people yield pounds with it. Anyways what Im gettin at is whats the EC? Would have to be really high for ph up or down not to work as good but coco for canna guy usually dont pass 1.5ec if that.

I do 1.7ec though one day suddenly and the only thing that changed is I went 3 gallon to 1 gallon pot not even full. I dont even check my ph anymore like its promix lol because lucky me 1.2 ec of maxibloom and .5ec tap water make a perfect 5.8 ish on the test drop kit.

Its a real thing I guess, a coincidental sweet spot that I can take advantage of. Not no 5ml a gallon ph up/down though maybe 5ml for a 55 gallon reservoir. I notice bacteria blooms spike ph out of range alkaline and harder to get back down. I just use 5 gallon buckets as reservoirs now, thats another story.

Click to expand...

Using my cheap meter I end up at around 600ppm. However the meter adjusts for temperature and the temp readings are always way off so I have to use math to adjust for the bogus variable. That is before I add ph down. the ph down raises it to close to 800. FWIW I did employ the RO filter and have gotten down to 1ml/gal. of ph down. It has only been 4 days. I am having trouble deciding if things are better but certainly are not worse.

Im guessing the paper strips are culprit maybe the ro water just makes them read different as ph is about ions and ro having none. Idk could be wrong as hell but just curious to see what the answer is, somethings unusual. Id try General Hydroponics ph test drop kit.

Using a ph meter improperly will yield bad results and even if you do, there will be a time it goes bad. Only you would notice if a sudden change in pattern. My ph meter when out and was adding 120ml of ph down to 55 gallons.

1ml of 100% phosphoric acid in a gallon would be ~100ppm

Most phosphorus products are 45-55%