3

In my hydroponic system, I need to control the ph level with natural household items without harming the plants. Currently, the ph level is very low (3). Any one know how to do this both ways?

  • And why are you limited to "natural household items" - (and what does "natural" mean in that case?) This frankly sounds most like a homework question, which makes me less inclined to answer it without clarification. You only learn from your homework by actually doing it - yourself. – Ecnerwal Jan 29 '18 at 1:24
  • 1
    @Ecnerwal Natural means "No harmful chemicals" – M Watt Jan 29 '18 at 1:36
  • 1
    Better get rid of the water then, I hear people drown in the stuff. {sure they die from lack of it too, but it can be harmful - which is another way of saying that's a very, VERY vague and essentially useless definition or criterion} Or salt - a bit won't harm you, too much will, and not much at all harms most plants. – Ecnerwal Jan 29 '18 at 1:44
  • 1
    If your water is pH 3, and you have copper pipes, you might have a problem with copper leaching from the pipes, which would not be good for you or your plants. It also makes the pipes leak, eventually. Decent quality test strips are quite reliable; poorly maintained meters are not, so if you are going to get a meter, take care of it properly (they are kinda fussy.) – Ecnerwal Jan 29 '18 at 19:08
  • 1
    You can just buy some bottled water, preferably from New Zealand, and test your pH strips. – Graham Chiu Jan 29 '18 at 23:43
3

I very much doubt that your tap water and deep water culture have a pH of 3. Nutrient lockout occurs below 5.5 yet your plants mostly seem okay based on your previous question. City water tends not to be acidic as that would corrode pipes.

Furthermore as plants take up nutrients the pH tends to rise and as you add nutrients the pH falls. So one would expect your water to be alkaline.

In flood and drain systems the pH might be too high if you had grow media with too much calcium carbonate, or concrete tubs. So to raise the pH you could add dolmitic lime. Baking soda contains too much sodium which your plants won't like. Some people use sea shells, and egg shells to help buffer the pH.

  • Oyster shell is commonly sold as a supplement for chickens, and will work similarly to limestone or marble chips. – Ecnerwal Jan 29 '18 at 19:11
  • @Graham Chiu You're exactly right! I bought a professional PH meter and tested. My solution have a PH reading of about 5.94. I think It's completely safe! Thanks for the help! – M Watt Feb 8 '18 at 10:17
3

Whether or not your household has any right now, probably the least likely to kill your plants common substance to raise pH would be ground limestone. In some systems limestone or marble chips are used, which last longer but act more slowly than the ground dust-like material.

  • 1
    I'd use Red Devil drain cleaner (sodium hydroxide), but that's probably not what M Watt means by a "natural household item". – Wayfaring Stranger Jan 29 '18 at 13:20
  • Most plants are intolerant of sodium, so neither sodium hydroxide nor sodium carbonate nor sodium bicarbonate are particularly good options for a plant system. – Ecnerwal Jan 29 '18 at 19:03
  • It should only take a few millimolar (0.04g/L) to get the pH up where it belongs. That's not enough to harm a plant. – Wayfaring Stranger Jan 29 '18 at 20:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.