DIY pH up with calcitic lime?

Im sure this has been discussed before but has anyone done this before? Just dissolve some of the lime into a jug and use it as pH up? I figure it will raise the pH as well as supply calcium; if I use dolomite lime then I also will get the added benefit of the Mg. I figure that the carbonate buffer also has a good buffering capacity as well. Just wondering if anyone has given it a shot yet. Thanks for the feedback.

- BD

The problem with lime is that it will also raise your carbonates. It's fine for soil, but in hydroponics, you're better off with potassium hydroxide flakes (KOH)

calcium nitrate is pretty much your only option to supply calcium in hydro. (also where most of your N should come from)

churchhaze said:

The problem with lime is that it will also raise your carbonates. It's fine for soil, but in hydroponics, you're better off with potassium hydroxide flakes (KOH)

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Would the ionic potassium interfere with my NPK ratios? And if thats the case should I just use NaOH instead?

BDGrows said:

Would the ionic potassium interfere with my NPK ratios? And if thats the case should I just use NaOH instead?

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Yes, KOH is 69.7% K by mass. When multiplied by K2O conversion factor (for NPK rating), KOH is 0-0-83.6.

NaOH would add unneeded sodium which antagonizes potassium uptake.

I know it doesn't help you much, but if I knew I always had to use lots of pH up, I'd use less KNO3 and K2PO4 and more KOH. I'm not lucky enough to have this problem though (hard water).

churchhaze said:

calcium nitrate is pretty much your only option to supply calcium in hydro. (also where most of your N should come from)

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Calcium sulfate is readily available

I think I am just going to prepare a 1M solution of KOH. Just keep it simple, hopefully, the excess potassium ions won't mess up my NPK to horribly...