[HEINEKEN357]

I have the red sea co2 test kit and i keep running out of co2 B Contains sodium Hydroxide and hate paying $15+ for another kit. Would Sodium Hydroxide Lye work says its for making soap, its cheap 2pounds for $5.

 

[Darkblade48]

Why are you using a CO2 test kit? They are generally not very accurate. It is better to use a drop checker with a known 4 dkH reference solution instead.

However, the solution B likely contains other chemicals other than the sodium hydroxide. Thus, buying sodium hydroxide that is used in making soap will likely not work. In addition, you never know how pure the sodium hydroxide you buy is (unless you get it from a reputable source).

 

[HEINEKEN357]

Ok thanks darkblade I have another drop checker on its way from china so its going to take some time doh. I mite try and make some 4 Dkh they say its pretty easy to make.

 

[elihanover]

I've never had luck with those test kits. Drop checker for the win.

 

[Darkblade48]

I mite try and make some 4 Dkh they say its pretty easy to make.

Just in case you don't have the instructions, here is an article written by billionzz.

http://www.plantedtank.net/forums/general-planted-tank-discussion/42429-kh-standard-how.html