Kh problems

[wasabi bean]

So i have a relatively new tank with only a few lps and one sps and i thought water changes would be fine, i never tested kh because of this, saw a decrease in growth and colouration and only now tested kh, i know stupid, and it is a 4.5. I have bought kalkwasser as i thought this would be the problem, how much should i dose, i have a 250l tank

 

[wasabi bean]

Also i used a salifert kh test, as i heard they are accurate

 

[Garf]

So i have a relatively new tank with only a few lps and one sps and i thought water changes would be fine, i never tested kh because of this, saw a decrease in growth and colouration and only now tested kh, i know stupid, and it is a 4.5. I have bought kalkwasser as i thought this would be the problem, how much should i dose, i have a 250l tank

If the result is real (that's extremely low), I'd use food grade sodium bicarbonate to gradually bring it up, not kalkwasser. There are a couple of caveats to that however. You need to make sure the salinity is good, and it's worth checking calcium, whilst you are at it. There's no harm in using kalkwasser to maintain the alkalinity and calcium when you are nearer your target however.

 

[Subsea]

So i have a relatively new tank with only a few lps and one sps and i thought water changes would be fine, i never tested kh because of this, saw a decrease in growth and colouration and only now tested kh, i know stupid, and it is a 4.5. I have bought kalkwasser as i thought this would be the problem, how much should i dose, i have a 250l tank

I saw a similar thread from you on December 17 and Randy Holmes Farley gave you a link to calculate


https://reef.diesyst.com/chemcalcnew.html