Currently feeding at 4.0-4.5 pH because I like to live dangerously!

[Peat_Phreak]

This is for the purpose of reducing media pH which has risen too high late in the grow. It appears to be working. It feels so naughty feeding at 4.0-4.5 pH. Anyone else try this?

 

[SofaKingHigh]

This is for the purpose of reducing media pH which has risen too high late in the grow. It appears to be working. It feels so naughty feeding at 4.0-4.5 pH. Anyone else try this?

Changing your input ph is not the fix for changing media ph. Your asking for nutrient lockout no doubt. If you give more info on your grow we could probably help you out.

 

[Peat_Phreak]

Changing your input ph is not the fix for changing media ph. Your asking for nutrient lockout no doubt. If you give more info on your grow we could probably help you out.

I wasn't asking for other alternatives. What I did is called an acid drench. It's one of a few ways to reduce media pH quickly. No lockout issues occurred and all the leaves are still flawless. The media pH lowered by 0.6 pH and normal feeding has resumed.

How was I 'supposed to do it' and why do you think what I did is wrong?

 

[jguit]

@Peat_Phreak is correct, you either acidify water or use an acidic fertilzer to drop the pH of soiless media.

 

[Homesteader]

Unbuffered peat will drop your pH pretty quick if you top dress it in. Can that not be used?
I have experimented in the past with vinegar and changing the pH quickly caused twists and curls in the new leaf growth. Never heard of an acid drench but sounds interesting.

 

[jguit]

Never heard of an acid drench but sounds interesting.

This is from the PTHorticulture (ProMix) website

"Bottom line is if you need to drop the pH of our growing medium, consider using acidic fertilizers or injecting acid into the water to neutralize the alkalinity that causes growing medium pH to rise."

This is the same advice I got when I contacted them via email.

 

[buhdda]

I read that like 3 times to figure if I gotten that right, 4.0 - 4.5 , He likes to live dangerously?

 

[Homesteader]

I would assume promix would probably not recommend straight peat. With the acid drench though, it seems like a temporary fix, no? I guess they are saying there is only so much lime in their mix and by neutralizing it, the acid in the peat or whatever else is in their mix can maintain it low. Little confused but og well, interested to see the results

 

[Cashmeh]

Gangster

 

[buhdda]

Gangster

live in St Louis if you think you're G

 

[Cashmeh]

live in St Louis if you think you're G

Who said I don't? This that show me state.

 

[buhdda]

Who said I don't? This that show me state.

exactly

 

[PK1]

nothing naughty or G about it. keep your shorts on!
i nuked my rockwool with ph 4.5 to get the ph levels inside rw back down to 5.5

 

[jguit]

I would assume promix would probably not recommend straight peat. With the acid drench though, it seems like a temporary fix, no? I guess they are saying there is only so much lime in their mix and by neutralizing it, the acid in the peat or whatever else is in their mix can maintain it low. Little confused but og well, interested to see the results

My understanding (or lack of) is that the buffering capacity of ProMix is 'not significant' (their words) and that the pH of the medium can be changed overtime by the acidity or basicity of the fertilizer being used or the alkalinity of your water. You can counteract this with using acids or using a different fertilizer (alternating applications). So you're right, it does sound like a temporary fix. Unless of course I'm missing something. I was also told that pH of the feed doesnt matter.

 

[buhdda]

My understanding (or lack of) is that the buffering capacity of ProMix is 'not significant' (their words) and that the pH of the medium can be changed overtime by the acidity or basicity of the fertilizer being used or the alkalinity of your water. You can counteract this with using acids or using a different fertilizer (alternating applications). So you're right, it does sound like a temporary fix. Unless of course I'm missing something. I was also told that pH of the feed doesnt matter.

that depends on your water, in my area I have to wait 24 hrs. to equal out otherwise it'll go up, 1 of the reasons my ph was going up in the very beginning

 

[jguit]

that depends on your water, in my area I have to wait 24 hrs. to equal out otherwise it'll go up, 1 of the reasons my ph was going up in the very beginning

I suppose but if you have to wait 24h to use your water it sounds like something else is going on or unrelated.

 

[PK1]

that depends on your water, in my area I have to wait 24 hrs. to equal out otherwise it'll go up, 1 of the reasons my ph was going up in the very beginning

you should get your cities water report and see whats in it that causes the problem for you.

 

[Peat_Phreak]

Bicarbonate in tap water is the main thing that increases the pH over time. The bicarbonate of my tap water is not high. It's about 70ppm before acid. This is usually low enough to not cause a pH rise problem when I acidify to 5.8. For whatever reason, the media pH got up to 7.3 this time. Problems can start occurring above 7.8, so I wanted to lower it quickly just to be safe with a few weeks to go. It worked.

I did an acid drench flush at 4.0 pH with 2-3 gallons of water per pot. Let it soak in for 12 hours. Then fed at 4.5pH. Did this for two feeding cycles. The media pH dropped down to the sixes. The plant's roots aren't drinking super low pH water in this scenario because the pH raises quite a bit a few seconds after mixing with the basic media.

 

[Peat_Phreak]

Just wanted to give an update on this. The 4.0ph acid drench / flush solved the issue. Rather than repeat this once a week, I just fed at 5.0ph for the rest of the grow. The runoff remained in the safe zone and it remained stable. pH went from mid sevens to mid sixes. Didn't develop any leaf defects.

I've heard people claim this method is a recipe for disaster. "You can't feed with the pH that low". Then they point to a nutrient uptake pH chart as 'proof'. Well, it's not a recipe for disaster. It's a valid method to solve an alkaline media issue quickly.

The plant isn't drinking dangerously hot acid water. The pH of the acid feed rises into the safe zone when it mixes with the alkaline media while simultaneously lowering the pH of the media to the desired range.

 

[fishbuds]

pics for us?