Who do i beleive?

[Notsolostfish]

I have hanna tds meter, ro in line readed, and cheap amazon tds meter. The hanna one shows 1, the amazon one shows 0, and the in meter reader reads 0. Is hanna tds meter more sensitive to salt residue from previous water change? And dust etc? Should i be worried about that

 

[EeyoreIsMySpiritAnimal]

I have hanna tds meter, ro in line readed, and cheap amazon tds meter. The hanna one shows 1, the amazon one shows 0, and the in meter reader reads 0. Is hanna tds meter more sensitive to salt residue from previous water change? And dust etc? Should i be worried about that

Hobby grade testers usually have a margin of error. I think you're probably fine

 

[Reefering1]

If they all read 0 out the ro unit, and you trust that your container is clean, I wouldn't be worried about