But I also like
Anyone used battery acid, sulphuric, for pH down?
Just been checking the interweb on this subject!
The answer is yes Sulphuric acid can be used once diluted with distilled water.
There are a lot of write ups on various forums but it seems some people don't know what they are doing, luckily someone generally swings in and gives the correct information.
Never add water to acid is the main safety advice as it can cause explosions and you really don't want exploding acid.
Second is to make sure you wear protective clothing/eye protection.
There is a very limited thread on AFN about it but not worth the read if you want to use sulphuric acid as PH down. Link here >>
https://www.autoflower.org/threads/ph-down-alternative.62188/
I would google it and you will find how it can be used, safety precaution and how to know the difference between "Battery Acid Fluid" and "Sulphuric Acid" which can be added to water in order to be used in batteries.
It seems there are a lot of people who work in auto stores who don't know the difference.
Personally I wouldn't bother with all the hassle and having to take precautions making the Sulphuric Acid in to a PH down.
PH Down costs so little and I also use very little to adjust the PH of my nutes, I can't really see the benefit.
If you do decide to go ahead and make it, please do as much research as you can and take ALL the safety precautions you can and do it straight and not under the influence! Pets, children and everyone else need to be out of the room too!