New Grower water ph and citric acid crystals beginner info

[hello]

where all can you buy citric acid crystals? is it all the same like pool products and such?
how is ph testing used? im guessing you test and adjust ph of water before watering. and I guess it might be possible to test ph of plant soil? please let me know how its done.
im a beginner. thanks for helping.

 

[dankle]

you can buy citric acid real cheap off ebay, was like $3 for 6oz shipped. I have a cheap Ph pen that cost maybe ten dollars.

Ive brought my guano tea down from a ph of 7+ to around 6 but after it continues to brew the ph seems to rise, so I am now adding more citric acid right before feeding to keep the ph around 6. Only takes a teaspoon or so with the tea, but its good to add slowly I've learned when my first brew dropped to a ph of 3.

 

[hello]

you can use a lemon to lower ph. only takes a small amount.
you can use baking soda to raise ph.

 

[Cptn Feathersword]

The problem is using these home remedy ph down products that they only last a few hours, after that your plant is drinking water that is out your intended ph range.
Make sure you use a good ph pen too with dual calibration screws or you really are just swinging punches in the dark lol.
Gh ph down dry isnt too expensive and will keep the ph stable until the plant as time to drink it all.

If you must persist with citric acid and vinegar type products make the ph very low as it starts to swing up almost immediately.