Quick question regarding alk increase

[Christopher Poore]

Hello all!

My tank is pretty stable at 8.9-9.1dkh at 8:00pm.

I did a 10% water change and my alk rose to 9.7 (yesterday at the same time it was 9.1) so a .6dkh raise.

Should I lower it slowly over the course of a few days by maybe reducing my autodoser amount? Or should I drop it back to 9.1 by turning off the doser until it reaches 9.1?

Thanks!

 

[jwshiver]

Did you check the dkh of your salt mix before you added to the tank? You can stop dosing and it will drop slowly enough on its own.

 

[Christopher Poore]

Did you check the dkh of your salt mix before you added to the tank? You can stop dosing and it will drop slowly enough on its own.

I did. It was 10.3. 10% change I anticipated a .2 change in dkh not a .6.

So you're saying turn off the doser entirely, let it get back to 9.1 and turn it back on? It'll probably drop to 9.1 by mid day tomorrow. Is that not too rapid of a decrease?

 

[jwshiver]

I did. It was 10.3. 10% change I anticipated a .2 change in dkh not a .6.

So you're saying turn off the doser entirely, let it get back to 9.1 and turn it back on? It'll probably drop to 9.1 by mid day tomorrow. Is that not too rapid of a decrease?

Yes, turn it off and monitor your alkalinity and turn it back on when it hits the number you want. It is hard to say how long it will take. It depends on how fast your system consumes it. Could be a day or two. Check it again in 24 hours after you turn your doser back on to see if you need to adjust the dosing amount. I've done this several times without a problem. Your dkh will swing over the course of 24 hours. I would not worry about .6 change.

 

[tutmatt3]

What type of salt are you using? Your dlh must have been @ 15 on the new salt to raise it .6 on a 10% wc

My suggestion, look into everything else as well. Maybe dosing too much, maybe bad sample for test, maybe bad salt! But something is def going on behind the scenes

Edit: and how long did you wait before testing your tank after the water change?

 

[Randy Holmes-Farley Verified Community Expert]

Might just be testing error.

Unless it is a very low nutrient system, there's nothing wrong with 9.7 dKH.