alk question about IO salt

[coolwheels]

I have been having a prob with high alk in my tank so I have been reading a lot of articals and doing a lot of testing my water from my ro+di unit is around 8.3 dks but when I add IO to water to the salinty of 1.026 it jumps to 16.7 is this normal and is there a way I can deal with this or a diff salt I can use THANKS

[Randy Holmes-Farley]

The not normal thing is to have any alkalinity from an RO/DI. Without that input, the alkalinity would be normal. The DI part of the RO/DI is depleted. It may be because the RO is also broken, so the DI is rapidly depleted.

Do you have a conductivity/TDS meter to know when to replace the DI?

[coolwheels]

no I dont have a meter I guess I got something else to buy THANK YOU

[Randy Holmes-Farley]

You're welcome.

This article may help:

What is TDS?
http://www.reefkeeping.com/issues/2004-04/rhf/feature/index.htm

and this one will help suggest how to lower the alkalinity by supplementing only calcium via calcium chloride for a while:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

[coolwheels]

I had allready read the alk one and it had helped a lot but the tds one is very informative THANK YOU AGAIN

[coolwheels]

I looked at the di beads today and they had change color . I change them and retested the test was reading over 11 and now smell like fish I am taking it in to a local ro/di guy tomorrow to have the system checked was unsucessful at finding a tds meter in our small town will keep you posted

[Randy Holmes-Farley]

There are a couple of possible sources of the smell. My water company uses chloramine. When the chloramine breaks down on the carbon, ammonia is released that is later caught in the DI. So the DI loads up on a lot of ammonia. When the DI gets shot, then much of this ammonia can be released to the product water as sodium and other things displace it from the DI. My water smells strongly of ammonia (a bit fishy) when the DI is spent.

New DI resins also sometimes have a slight fishy smell from traces of amines in the cartridge. After a gallon or two, this usually goes away.