pHing the water, then adding fertilizer?

[MIGrampaUSA]

pH up and down are not buffers. Whoever told you that was confused. Soil can be a buffer.

I agree with your method — nutrients and additives can change pH. Adjust afterwards.

I am skeptical of the blanket statement by some organic growers, saying irrigation water doesn't have to be adjusted for pH. That doesn't fly if you have a lot of minerals in your water. Soil is a buffer, but all buffers have a capacity. Once that capacity has been reached it can't help you.

Organic grower here ...

pH up is a base. pH down is an acid. Buffers perform a chemical reaction to adjust pH.

There's good reason to be skeptical of any "blanket" statement. In my case, I use 2 stage filtered water ... 1 stage removes chlorine/chloramines and the 2nd removes dissolved solids so while the filtering doesn't change the pH of the water itself, it does remove the buffering minerals so that the soil doesn't have to work as hard and the buffering capacity of the soil should easily last the length of a full 3 - 4 month grow cycle. I'm not sure I would say the same about extremely hard well water unfiltered as this would surely alter soil pH after a couple of months of use.

A lot of whether or not a blanket statement like above is true depends on the source water. The flip side is because mine is filtered, I end up adding more magnesium and to a lesser extent calcium back to the mix than others might. Where as someone with a known hard water source might do better using nutes designed specifically for hard water. Some of the companies are offering "hard water" formulas ... not sure if they're organic or even if that matters to the OP as I've not researched them. I'm simply aware that they exist and for some growers, have changed the quality of their grows.

 

[mysticepipedon]

Organic grower here ...

pH up is a base. pH down is an acid. Buffers perform a chemical reaction to adjust pH.

There's good reason to be skeptical of any "blanket" statement. In my case, I use 2 stage filtered water ... 1 stage removes chlorine/chloramines and the 2nd removes dissolved solids so while the filtering doesn't change the pH of the water itself, it does remove the buffering minerals so that the soil doesn't have to work as hard and the buffering capacity of the soil should easily last the length of a full 3 - 4 month grow cycle. I'm not sure I would say the same about extremely hard well water unfiltered as this would surely alter soil pH after a couple of months of use.

A lot of whether or not a blanket statement like above is true depends on the source water. The flip side is because mine is filtered, I end up adding more magnesium and to a lesser extent calcium back to the mix than others might. Where as someone with a known hard water source might do better using nutes designed specifically for hard water. Some of the companies are offering "hard water" formulas ... not sure if they're organic or even if that matters to the OP as I've not researched them. I'm simply aware that they exist and for some growers, have changed the quality of their grows.

I think the issues I have with my water is both high pH (about 7ish) and high calcium. The pH down I use is phosphoric acid and I believe the P combines with the Ca in the water and makes it less available to the plants. During my last grow, I think calcium reduced P and K uptake.

I should really filter my water in some way.

 

[MIGrampaUSA]

I think the issues I have with my water is both high pH (about 7ish) and high calcium. The pH down I use is phosphoric acid and I believe the P combines with the Ca in the water and makes it less available to the plants. During my last grow, I think calcium reduced P and K uptake.

I should really filter my water in some way.

Calcium will precipitate out of a solution at lower pH's ... it also does interfere with P and K uptake. So yes, I think you're on to something. Try epsom salts at about a teaspoon per gallon instead of cal-mag. I suspect you'll see improvement.

A filter setup doesn't have to be expensive. Mine is a 3 stage RO unit with the RO part of the filter bypassed so I'm only using 2 of the 3 stages. It cost me $75 and could probably be found for less.

 

[freezeland2]

I've been adding diamectous Earth, especially at the beginning which has some silica in it, when I was having a problem with gnats and a few other creepy crawlies, thankfully have had not seen any insects for a while.

What kind of silica do you add?

If the poster is using dyna-gro they are probably referring to this as a silica supplement. Pro-TeKt which isn’t silica but a replacement for it.

 

[SunshineSupergirl]

Organic grower here ...

pH up is a base. pH down is an acid. Buffers perform a chemical reaction to adjust pH.

There's good reason to be skeptical of any "blanket" statement. In my case, I use 2 stage filtered water ... 1 stage removes chlorine/chloramines and the 2nd removes dissolved solids so while the filtering doesn't change the pH of the water itself, it does remove the buffering minerals so that the soil doesn't have to work as hard and the buffering capacity of the soil should easily last the length of a full 3 - 4 month grow cycle. I'm not sure I would say the same about extremely hard well water unfiltered as this would surely alter soil pH after a couple of months of use.

A lot of whether or not a blanket statement like above is true depends on the source water. The flip side is because mine is filtered, I end up adding more magnesium and to a lesser extent calcium back to the mix than others might. Where as someone with a known hard water source might do better using nutes designed specifically for hard water. Some of the companies are offering "hard water" formulas ... not sure if they're organic or even if that matters to the OP as I've not researched them. I'm simply aware that they exist and for some growers, have changed the quality of their grows.

I've been using a Brita water filter.
It actually changes the pH just a little bit compared to tap water.

The more important thing is it's a cleaner water, it tastes better to me so I'm pretty sure it tastes better to my plants.

 

[Treecutter]

That depends on what the pH is after you add nutes. If it's in the desired range, then you can skip lemon juice.

It also depends on how much bicarbonate your water has. If your water has high bicarbonate, you can pH to the ideal range and still get rising media pH and lockout problems. To correct this, use RO water or acidify to 4 pH, then add nutes then pH UP to the desired range.

She's going to get a rise anyway in her soil because of the diatomaceous earth. She's fighting herself on both ends on the ph and adding nutes.

Think her best bet for help is to go do some reading in the learning threads. She nuked her seedlings in her first post.

 

[Treecutter]

I've been using a Brita water filter.
It actually changes the pH just a little bit compared to tap water.

The more important thing is it's a cleaner water, it tastes better to me so I'm pretty sure it tastes better to my plants.

Not sure on britta, they either and minerals and electrolytes or let them pass through otherwise the water would taste horrible.

I use RO when adding nutes and declorinated tap when not adding nutes through the bypass before my RO filter.

But that being said, the only thing added to water throughout my grow is Epsom salt and starches in flower because my soil media is built with most my nutes and I top dress every 3 to 4 weeks or a compost tea if I got behind on a feed

Seedlings are just in coco, perlite and worm castings.

If you want to know whats going on in your soil, take a measurement of the run off water.

Tap water in my are is over 600 ppm. Well water in this area can be as alkaline as 8. I grow in a coco base mix and don't have any issues with the ph in my soil base when I ph my water after adding nutes.

This plant is at week 6 of flower