Making Slabs With New Materials

[yashu]

I was just looking at the safety data sheet and noticed it has a pH of over 11 so you may want to plug up your drain holes, let some water stand in it a while, and then check the pH. Assuming it has adequately leached over the winter you may have knocked down the pH to the point it won’t burn plant roots, but I would definitely check before using.

Not an expert here but I think all cement products are extremely basic before they are activated and set, it’s part of the reaction that makes it harden. I can’t imagine it would remain that caustic once it has set and the reaction stops.

 

[yashu]

Well, looks like I was off. Did a little Google research and found that many concrete products do retain high ph for some time. Some processes that occur with time can lower the ph. This is pretty interesting though since concrete pots are not uncommon and I have yet to hear that they kill trees.

Some more info;

Concrete pH – Floor Expert

www.floorexpert.com

 

[WNC Bonsai]

Well, looks like I was off. Did a little Google research and found that many concrete products do retain high ph for some time. Some processes that occur with time can lower the ph. This is pretty interesting though since concrete pots are not uncommon and I have yet to hear that they kill trees.

Some more info;

Concrete pH – Floor Expert

www.floorexpert.com

I have seen websites on concrete slabs where they always leave them out in the weather for a year to lower the pH. This is also commonly done when making a concrete pond. I wonder whether spraying the slabs with vinegar or some other acid will speed the process?

 

[Wulfskaar]

I have seen websites on concrete slabs where they always leave them out in the weather for a year to lower the pH. This is also commonly done when making a concrete pond. I wonder whether spraying the slabs with vinegar or some other acid will speed the process?

I just read on yashu's link that you shouldn't do that because it may cause buildup of salts on the surface.

 

[WNC Bonsai]

I just read on yashu's link that you shouldn't do that because it may cause buildup of salts on the surface.

Well, looks like I was off. Did a little Google research and found that many concrete products do retain high ph for some time. Some processes that occur with time can lower the ph. This is pretty interesting though since concrete pots are not uncommon and I have yet to hear that they kill trees.

Some more info;

Concrete pH – Floor Expert

www.floorexpert.com

Interesting since various pond sources recommend either filling the pond and draining until the pH is acceptable of treating with vinegar. Where is @Leo in N E Illinois when you need him?

 

[Gabler]

The chemical reaction in the cement continues over time, gradually making the concrete harder. I would worry that an acid bath would stop the hardening of the cement and weaken the concrete.

 

[Hartinez]

Ive got these all soaking in water now in fact, plus I had been spraying them down as constantly as possible over the winter. I will also be curious to see how trees respond to the conditions. But ultimately, I'm not worried and excited for the maiden voyage on all of these slabs!

 

[radhatter]

Ive got these all soaking in water now in fact, plus I had been spraying them down as constantly as possible over the winter. I will also be curious to see how trees respond to the conditions. But ultimately, I'm not worried and excited for the maiden voyage on all of these slabs!

Any chance you’re able to test water that’s been standing in the pot for a while?