Can't get my runoff PH down! Help please or they will die!!!

CustomHydro

CustomHydro

Well-Known Member
Can't get my PH down!! I have tried everything. I have flushed with 2.5 PH'd water ant it still comes out well over 6. I'm killing the plants either from PH down or from a high PH at this rate so I need a fix fast. I pre soaked the RW in 4.5 PH water over night and I woke up the PH was 7, then I soaked it in 3.0 water and it came out at 6 at the 24 hour mark, so I used it. A few days later it was back up to 7. It seems like no matter what I do the PH stays at 7 They are dying slowly from high PH and I don't know what to do. They are water logged to shit the leaves are curling over, under, twisting in circles, it's terrible. I have 9 plants in 2gal containers and I have flushed with 90 gallons. 50 gallons ph'd at 5.0 and 40 gallons ph'd at about 3.0.
 
CustomHydro

CustomHydro

Well-Known Member
Yes they were, they were in absolutely terrible shape. Then I gave them a good flush and feed, left for vacation and I came back and they had taken off good. I left them alone, i thought I had it solved. Slowly the problems started to come back and worsen.
I may have somewhat of an explanation, RW has a ton of limestone, which will cause a high PH (I believe). I found a guy who says not to soak it over night but to flush tons of water thru it, even if it is just tap water. That will get rid of the limestone and then I can adjust the PH easily after that. What do u think? The only problem I have with this is , are the minerals from the tapwater going to stick in the RW and need to be flushed out just as much as the limestone?
 
Florida Girl

Florida Girl

Well-Known Member
CustomHydro said:
Can't get my PH down!! I have tried everything. I have flushed with 2.5 PH'd water ant it still comes out well over 6. I'm killing the plants either from PH down or from a high PH at this rate so I need a fix fast. I pre soaked the RW in 4.5 PH water over night and I woke up the PH was 7, then I soaked it in 3.0 water and it came out at 6 at the 24 hour mark, so I used it. A few days later it was back up to 7. It seems like no matter what I do the PH stays at 7 They are dying slowly from high PH and I don't know what to do. They are water logged to shit the leaves are curling over, under, twisting in circles, it's terrible. I have 9 plants in 2gal containers and I have flushed with 90 gallons. 50 gallons ph'd at 5.0 and 40 gallons ph'd at about 3.0.
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Something sounds off here. When was the last time you cleaned and calibrated your meter?

Also.... how long are letting the probe sit in the runoff before you consider the reading stable? In other words.... are you just dropping the probe in for 1 minute and taking the 7 reading as the PH reading? I let my probe sit for 15 minutes before I consider the reading stable.

I just don't see how you could flush with 50 gallons at 5.0 and 40 gallons at 3.0 and still have a runoff of 7.0.... something is not right here.
 
del66666

del66666

Well-Known Member
tap water isnt that bad, go with what u think, id say your big prob is how wet thy are , water log can drown a plant as im sure u r aware, get kitchen paper underpots to draw water out. i tend to use smaller pots for more control,lime yeah its what gardeners use to alter ph .good luck, keep us posted
 
CustomHydro

CustomHydro

Well-Known Member
Florida Girl said:
Something sounds off here. When was the last time you cleaned and calibrated your meter?

Also.... how long are letting the probe sit in the runoff before you consider the reading stable? In other words.... are you just dropping the probe in for 1 minute and taking the 7 reading as the PH reading? I let my probe sit for 15 minutes before I consider the reading stable.

I just don't see how you could flush with 50 gallons at 5.0 and 40 gallons at 3.0 and still have a runoff of 7.0.... something is not right here.
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My plants are in 2gallon pots and I have 9 of them. I flushed each plant witth about 10 gallons. Some plants have now had over 20 gallons ran thru. My PH meter isn't perfect, it does need a new probe but it's readings are close. I have 7.0 and 4.0 calibration solutions and it's in the ballpark with those everytime. It gets within 1.0 within a minute or 2, but it won't give a stable reading for over an hour or 2. I will go get a cheap PH kit from the Hydro shop when it opens, that will hold me over until my new probe comes.
Oh yeah, I calibrate monthly and I clean it every once and a while, but all I do is wipe the probe off with a cloth, am I missing something?
Thanks
 
CustomHydro

CustomHydro

Well-Known Member
So far it looks like I was close before, I flushed each plant with 4-5 more gallons PH'd at 5.0 and they are under 6.0PH, according to GH Hydroponics Vial test kit, and my electronic meter. I talked to a couple people and I was told that the bulk Grodan RW that I am using is a lot more compact than other RW so it takes forever to get the lime off, especially when u have over a gallon of it in each pot. If someone reads this and is about to use bulk Grodan or any bulked RW, take my advice and flush the RW before u grow in it, don't just soak it in PH'd water, but litterally flush about 15 gallons of 5.0 PH water thru each gallon of RW. I also would suggest adding a very weak 1/4 seedling strength nutrient solution to the final flush to get a small amount of food for the plants in there to start them out healthy.

Edit, never do what I did with the really low PH water either, it doesn't matter if u flush with 0.5 PH'd water it will still take the same amount to get rid of the limestone, and as long as u have limestone u will have a high fluctuating PH and very very unhappy plants. Not to mention a strong acid solution will damage roots beyond belief.
 
Sara the Poet in my Heart

Sara the Poet in my Heart

Active Member
CustomHydro said:
So far it looks like I was close before, I flushed each plant with 4-5 more gallons PH'd at 5.0 and they are under 6.0PH, according to GH Hydroponics Vial test kit, and my electronic meter. I talked to a couple people and I was told that the bulk Grodan RW that I am using is a lot more compact than other RW so it takes forever to get the lime off, especially when u have over a gallon of it in each pot. If someone reads this and is about to use bulk Grodan or any bulked RW, take my advice and flush the RW before u grow in it, don't just soak it in PH'd water, but litterally flush about 15 gallons of 5.0 PH water thru each gallon of RW. I also would suggest adding a very weak 1/4 seedling strength nutrient solution to the final flush to get a small amount of food for the plants in there to start them out healthy.

Edit, never do what I did with the really low PH water either, it doesn't matter if u flush with 0.5 PH'd water it will still take the same amount to get rid of the limestone, and as long as u have limestone u will have a high fluctuating PH and very very unhappy plants. Not to mention a strong acid solution will damage roots beyond belief.
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The 7 ph won't kill them ...all the flushing and adding low ph stuff will...They can grow just fine with a ph runoff of 7.0. Just get your ferts and h2o at about 5 and keep them there and quit flushing and drowning them...:sad:
 
OregonMeds

OregonMeds

Well-Known Member
Sara the Poet in my Heart said:
The 7 ph won't kill them ...all the flushing and adding low ph stuff will...They can grow just fine with a ph runoff of 7.0. Just get your ferts and h2o at about 5 and keep them there and quit flushing and drowning them...:sad:
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Yep yep. Spot on.


But the op is right about how far off some of the rockwool is.
 
CustomHydro

CustomHydro

Well-Known Member
Sara the Poet in my Heart said:
The 7 ph won't kill them ...all the flushing and adding low ph stuff will...They can grow just fine with a ph runoff of 7.0. Just get your ferts and h2o at about 5 and keep them there and quit flushing and drowning them...:sad:
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Thanks, I'm afraid the advice may be too late, but it is exactly right. I did stop flushing with with low PH water a week ago, I also repotted them at the same time. The plants are not dead but they completely stopped growing at that point I repotted them. I think I damaged the roots severely with that acid water I was flushing them with. The older growth looks good, but the newer growth is completely yellow and not moving at all. Do u think they will recover? Is there a product I can use for root recovery? Thanks everyone, I appreciate it very much!
 
CustomHydro

CustomHydro

Well-Known Member
Well, they made a huge recovery yesterday. Thank god! They all perked up after being waterlogged for over a week, and I even see some new growth.
Thank u all for helping me out
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