high kh

[manners]

what happens if your carbonate hardness is high in a in a reef tank?
it was reading 20 dkh
how do you lower it??

 

[bang guy]

If it get too high (20 dKH certainly qualifies) it will precipitate Calcium carbonate, drop PH and reduce Magnesium.
With a dKH of 20 the first thing to do is confirm the reading using another test kit. If it really is 20 then make a large batch of new saltwater and test it. If it's good then do as large a water change as you can manage.

 

[manners]

what if the new batch is still high???

 

[bang guy]

Originally Posted by manners
http:///forum/post/2910952
what if the new batch is still high???
If you verified the test kit against a different kit and new saltwater shows dKH of 20 then you need to return the salt because you have a bad batch.
** edit - are you using tap water?

 

[manners]

ive tested the new batch and it reads 13 dkh. and i am useing tap water.
do ro systems help reduce kh?

 

[bang guy]

Originally Posted by manners
http:///forum/post/2910979
ive tested the new batch and it reads 13 dkh. and i am useing tap water.
do ro systems help reduce kh?
I don't see a problem with new saltwater having a dKH of 13. That's about right IMO.
RO systems remove all Carbonate and Borate (and most everything else) from the source water. So, in a way the RO will reduce KH. It's not an advertized attribute since Carbonate is the most common additive for saltwater systems.

 

[steelytom]

KH test kits are known to go bad and give false readings. Take a sample to the a LFS and have them verify. Do not do anything drastic unless you see a problem. Swings in kh can be worse than a high kh