PH ruining my grow please help!

[Irishsmoke00]

My grow is 4 weeks into veg today. I started with some issues, but was able to fix almost all of them. The one, which happens to be the most important, is my PH. I have a new meter plus the strips for backup. My tap water is about 7.5-8 PH, and when I put it in a cup and add ph down it goes to 5.5! But when I add ph down to my rez it doesn't do anything! I have completely cleaned the entire system including the buckets tubes pump airstones and rez! Like I said I got a H down into the rez and then test half hour or so later its still at 8! I am losing my mind and my grow! Does anyone have any suggestions for me? They would be unbelievably appreciated!

 

[Stilletto]

Well I can't help much.... it should go down accordingly from cup to res?... seems strange... rarely do I hear "alkalinity" used in pot growing... it buffers ph from fluctuating. In hot tubs it must be considered to keep the ph from moving.... never really considered it when it comes to growing but could be a factor?

Jonny

 

[KarlJay]

I assume you're doing a hydro and using acid form of PH down. You mention you're adding acid to a cup to get 5.5, how many cups are in your system?

Have you tried treating a larger amount of water? maybe take a gallon at a time and work with that?

My point is that if you get 1 cup of 5.5 and several gallons of 8, that's not going to make much difference... take 1/2 the water at a time, get it to 5.5 and then retest...

 

[DrOfDank]

This is going to sound like a stupid question, because it is, but are you putting the same amount of PH down in your res as you did the cup? If so, of course it isn't going to go down. Put more in.

 

[Irishsmoke00]

No Ive added a bunch to the rez and still no change. The only thing I can do now is get a really good RO filter, does anybody have any suggestions on some good ones? Also my plants are in weef 5 of veg, healthy but not growing anywhere near where they should be at I am assuming because they aren't really eating because of the damn ph being so high!!! If this is correct should I just veg for longer once I correct my ph? One last question, I just noticed like some white stuff on the grow cubes and a little on the hydroton around one of my plants, does anyone know what that could be?

 

[Cultivator]

salt build up is most likely the cause of white stuff. exactly how are u growing? and what is ur res size? what type of ph down are u using? nitric acid or phosphoric. post some pics and give me this info and i should be able to hrelp. also what type of ph meter are u using?

 

[oldman60]

If you are putting in a large amount of ph adjuster and not seeing any change it seems to me it has to be the stuff you are using.

 

[Irishsmoke00]

Im growing hydoponically in an oxyponics pro 6. I have a 50 gallon rez and im using phosphoric ph down. I have a 3 in 1 ph ppm water temp meter but im pretty sure the ph wasn't calibrated right so I also have the strips as backup.

 

[Jimmycricket]

first off, if your meters are not reliable then your reads can not be reliable. Get your meters calibrated, otherwise they are worthless.

Secondly for a 50 gallon res you would need to be adding quite a bit to bring a ph from 8 down to say 5 - 5.5, it would depend on the stuff you use but it would probably be about 1/4 of a cup of ph down!!! As on a per gallon basis it takes like 2-4 drops to bring my ph from 7.2 down to 4.7-5.2

But directly about your findings about the ph never dropping. Thats not possible given you are using a real ph down. The problem lies in one or multiple of a few factors.

Your meters need calibration
you are not adding enough ph down solution
your solution is not good.

It is not physically possible to keep adding ph down and have no change.

 

[Cultivator]

yeah agreed ^.

also u dont want to be using phosphoric acid in veg if u can help it. nitric acid is more suitable. in a 100litre res (25gal) i add about 12ml of ph down. but it depens how concentrated ur ph down is and how hard ur water is too. if u arent seeing any shift but u are seeing a shift in small amounts of water just try adding more ph down first.

 

[gardener]

I searched the site for oxyponics, and here I am. I realize this post is over six months old, but I had a problem with PH in my oxyponics 6 that may be similar to yours. I doubt you or anyone else made the same mistake I did, but just in case:

My first (and so far, only) grow had been going fine for weeks, and then I started having high PH. Even soon after res changes.

Turns out I wasn't properly draining the entire system. I had originally tried to drain the system through the control bucket when I first got the system, and nothing would come out. Then a forum member suggested I use a submersible pump in the res, and I thought everything was going well. I had the submersible pump in the res, no problem there... but... I wasn't draining the control bucket. So I got what I think is called a "nute pocket". The liquid remaining in the control bucket and the 6 grow buckets was not being drained each week when I drained the res. That remaining liquid had nutes in it, which kept building and building up over the weeks to toxic levels. It turned the leaves yellow and crispy crunchy. I did finish the grow, med was mediocre at best.

And I only figured it out after I quit in frustration and dismantled my entire system, but then re-read the users manual three times over.

Next time I plan to use an in-line pump to empty the control bucket separately from the res each week.

... I recently set up my system again, but cracked the control bucket when I was slipping my own hoses on the nipples (not the provided hoses). Manufacturer said they'd frankenstein the parts from my cracked control bucket onto a new bucket at their store for $150. (They wanted $300 for a complete new control bucket.) Those services and prices apply to units still under warranty, which is three years. I'm going to try sanding then gluing the crack with a glue made for underwater marine uses. Cheap fix that I hope works.