Dolomite lime problems if correct pH water?

[kronicking]

Hi, I am wondering if anyone can help me understand. Why would you want to use dolomite lime if you correctly ph your water. Wouldn't it just cause issues by raising the ph? Also why would someone want their ph to be 7. Isn't that high? I feel like dolomite lime was causing me problems because I did a slurry test of my sunshine mix #4 and it came out at a high ph when I had my water correctly ph'd. So I decided to make it a little more acidic than normal (5.7 ph instead of 6.2 ph) and slurry tested first and found it came to 6.2 ph so I watered to runoff with the 5.7 ph water and the runoff came out at 6.2 ph and my plants seem to be doing a lot better. They used to get what looked like nutrient deficiencies and nutrient burns.

 

[Emilya Green]

Hi @kronicking and welcome to the forum!

I think I can help. You are totally misunderstanding the pH thing and why we worry about it. First, your soil. Soil is intentionally set to have a base pH up near the upper end of the usable pH range in soil, or about 6.8 pH. This is the base pH, which is mostly set by adding dolomite lime at the soil manufacturing company so that when the soil is dry, it achieves this base pH.
Now we also know that mathematically, the most nutes are the most mobile in soil (available to the plants) at the pH of 6.3. So when we water, an wise gardener will pH adjust her fluids to 6.3 pH right before applying them to the soil. The shear volume and molecular weight of all that water set to 6.3 pH takes over, and while the soil is saturated (you watered to runoff) that soil/water saturation's pH will have to be 6.3.

As the plant begins to use that water, the water table in your container drops, and steadily from the top to the bottom, the soil begins to dry out. As it dries, two things are happening. First, the dolomite in the soil is beginning to influence the water that you gave, so it's pH is starting slowly to rise. Also, as the soil dries out it loses the influence of the lower pH adjusted water, and that section of the soil's pH begins to rise also.

What this does is drift the pH of the soil/water/nutes through the entire usable range of pH in soil, from 6.2-6.8 pH. It was designed to work this way so that all you have to do is water at 6.3, and the system takes care of itself. If you overthink this and try to overcompensate by coming in lower, thinking that you are somehow adjusting your soil, you are doing this all wrong. Stop fighting the system, and work with it as it was designed to be used.

I hope this helps! Good luck with your grow!

 

[Weaselcracker]

Your sunshine mix is working perfectly. SM is buffered to around 6.2, give or take a little. You can throw almost anything at it, very acidic or very alkaline, and the slurry/container ph will level off in the low sixes, usually within minutes. You can easily test this yourself with your ph meter.
A little more info from the Sunshine Mix company PH expert here Do we need to pH adjust our nutrient solutions?

And a test grow in SM where I ran two clones - using extremely high (10+) vs extremely low (under 4 ) nutrients solutions.
They flowered to harvest looking exactly the same as the ones I ph adjusted to 5.7.

Do we need to pH adjust our nutrient solutions?

Well if you ever wanna try the simplist method I've found I'll gladly share with ya.

www.420magazine.com

 

[farside05]

Your sunshine mix is working perfectly. SM is buffered to around 6.2, give or take a little. You can throw almost anything at it, very acidic or very alkaline, and the slurry/container ph will level off in the low sixes, usually within minutes. You can easily test this yourself with your ph meter.
A little more info from the Sunshine Mix PH expert here Do we need to pH adjust our nutrient solutions?

And a test grow in SM where I ran two clones - using extremely high (10+) vs extremely low (under 4 ) nutrients solutions.
They flowered to harvest looking exactly the same as the ones I ph adjusted to 5.7.

Do we need to pH adjust our nutrient solutions?

Well if you ever wanna try the simplist method I've found I'll gladly share with ya.

www.420magazine.com

^^^ This

Sunshine Mix or Pro Mix is not soil. It is a peat based soil-less mix (peat & Perlite). It is already buffered with lime. Peat is acidic on its own and is around 4.5 which is why they add the lime. Not sure in the exacts on Sunshine but Pro Mix is buffered to about 5.8 and I think Sunshine is similar. Your soil-less mix will need fed nutrients on every feed since it's inert and contains no food for the plants. Beyond that, there is no need to pH the input water/feed solution. The buffers (lime) in the Sunshine Mix will take care of that for you (see the links in @Weaselcracker post). PS, it takes about 3 days of being wet for the lime in a soil-less mix to balance the pH of the peat. If you are doing a slurry test prior to that point you won't get a good reading. You shouldn't have to concern yourself with that too much though. The fine folks at Sunshine and Pro-Mix have been at this a while and have worked that all out for you.

 

[Weaselcracker]

PS, it takes about 3 days of being wet for the lime in a soil-less mix to balance the pH of the peat. If you are doing a slurry test prior to that point you won't get a good reading.

I did a ton of slurry tests with SM, after a conversation with Emilia where she said that it takes a lot of time and a drying process for the ph to swing. Maybe that’s true for some final late stage adjustments but in my slurry tests the ph would generally settle to around 6.2-ish within a couple minutes. Stronger more extreme ph nutrient solutions seemed to take a little longer to settle, but the bulk of the ph shift always happened very quickly. I took a ton of photos and notes but in the end there wasn’t much worth saying about it beyond that.

The OP can easily test this with a ph meter and it’s a worthwhile thing to do just to settle the mind.

But basically as said. You do not need to adjust the ph of your nutrient solution using Sunshine Mix.

 

[kronicking]

weird. I don't understand why my plants are doing so much better with the 5.7 ph water compared to the 6.3 ph. I was getting all sorts of problems and now they all disappeared. The only thing I can think of is that slurry test came out at 6.3 ph when I added the 5.7 ph water. When I did 6.3 ph the slurry came out to 6.7 ph. I guess maybe it is just drifting up in the usable ph ranges like emilya said. I never changed my added nutes while I did this either. The one thing that I don't understand is that people say you don't have to ph at all for sunshine as it doesn't make sense that if I added my 7.3 ph water from my tap (after sitting out for chlorine evaporation) to the mix that I wouldn't have a high ph? I am starting to think that I got a bad bail as all the responses seem to say my ph shouldn't be a problem.

 

[farside05]

But basically as said. You do not need to adjust the ph of your nutrient solution using Sunshine Mix.

My meter has been getting dusty for over a year with my homemade version of Sunshine/Pro-Mix (aka Faux-Mix®). I need to throw out the bottle of pH Down I have too but the spiders need somewhere to hang out.

 

[Weaselcracker]

weird. I don't understand why my plants are doing so much better with the 5.7 ph water compared to the 6.3 ph. I was getting all sorts of problems and now they all disappeared. The only thing I can think of is that slurry test came out at 6.3 ph when I added the 5.7 ph water. When I did 6.3 ph the slurry came out to 6.7 ph. I guess maybe it is just drifting up in the usable ph ranges like emilya said. I never changed my added nutes while I did this either. The one thing that I don't understand is that people say you don't have to ph at all for sunshine as it doesn't make sense that if I added my 7.3 ph water from my tap (after sitting out for chlorine evaporation) to the mix that I wouldn't have a high ph? I am starting to think that I got a bad bail as all the responses seem to say my ph shouldn't be a problem.

Follow the links I gave above and you may or may not get a little more insight. I’ve been growing my weed in SM#4 for the last six or seven years. During almost all this time I adjusted my pH and was convinced I had PH problems if I went outside the range. But I must have been fooling myself.
Yes I’m still tempted to ph my nutrient mixes. And it’s not going to actually hurt your plants if you do- so it can work as a placebo. But it is hard to argue with the PH expert from the company that makes the stuff, and even harder to argue with my own test results.

 

[farside05]

The alkalinity of your water and the type of nitrogen used in your fertilizer has WAY more to do with your root zone pH than the pH of the solution you pour in. Like 100x more. Rather than rehash it all here, Follow @Weaselcracker 's link. It's all hashed out there.

 

[kronicking]

I feel like I must have a bad bail or something because I don't know what changed other than the ph I put in but I have no idea. If it was a bad bail I would assume I would still have the same problems due to the ph being adjusted to the same ph I had before so I really don't know. Like I said I was getting so many nutrient deficiency and nute burn symptoms it was ridiculous I was starting to think it was root rot or something. I guess I will just have to keep and eye out and right now just do what is working for me right now and see if something changes. I thought I might add that I am using remo nutrients supercharged kit.

 

[farside05]

I thought I might add that I am using remo nutrients supercharged kit.

Can't give you any advice there. Got 2 kits sitting here for about a year but never tried it, probably won't either. The dusty pH meter and spider webbed pH Down are sitting on top of the boxes. . Also have some Kelp Extract too. Must have a hoarding problem. I need to let go and just throw some of this in the trash.

 

[Weaselcracker]

I used to sometimes think I had a ‘bad bale’ or something. Probably grower error or misconception is far more likely. This stuff isn’t difficult to make.
The Remo nutrients you mention are the same ones I have, which they give away for some 420 contests. They’re regular hydro nutes and shouldn’t affect anything that has been already said.

 

[Chronic cultivator]

weird. I don't understand why my plants are doing so much better with the 5.7 ph water compared to the 6.3 ph. I was getting all sorts of problems and now they all disappeared. The only thing I can think of is that slurry test came out at 6.3 ph when I added the 5.7 ph water. When I did 6.3 ph the slurry came out to 6.7 ph. I guess maybe it is just drifting up in the usable ph ranges like emilya said. I never changed my added nutes while I did this either. The one thing that I don't understand is that people say you don't have to ph at all for sunshine as it doesn't make sense that if I added my 7.3 ph water from my tap (after sitting out for chlorine evaporation) to the mix that I wouldn't have a high ph? I am starting to think that I got a bad bail as all the responses seem to say my ph shouldn't be a problem.

Always test and balance your ph levels directly before you water....2nd Indica plants do so much better with a lower ph...therefore know your strains...Indicas thrive in a ph range of 5.5 to 6.5...varying the ph levels allows for different nutrients to enter the root system...less chance for nutrient burns...so don't be afraid to mix it up....and know that indicas like it around max temp of 25 to 27 C...even if you are enriching with C02...good luck!!!