Alkalinity won't go down

[laverda]

Something is definatly wrong with you RO/DI system. The DKH coming out of it should be zero. That is high enough I wonder if your output and waste lines are mixed up coming out of you RO membrane. What is the DKH of your tap water? My guess is 5 or a little lower.

You can use a few small amount of Muriatic acid to lower the DKH of your new salt water. There is a thread in the chemistry forum about how to reduce your ALK. Also lowering your salinity to 1.025 will help a little.

 

[droog]

Testing dKH of RODI water using a saltwater test kit might not give a "valid" result.

Testing TDS of your RODI is absolutely valid. TDS of water from your RODI water should be close to zero (or actually zero if you run a DI stage). If you never change the DI resin, I believe it can leak ions into the output water. Perhaps thats your problem.

-droog

 

[gaby_scan]

Something is definatly wrong with you RO/DI system. The DKH coming out of it should be zero. That is high enough I wonder if your output and waste lines are mixed up coming out of you RO membrane. What is the DKH of your tap water? My guess is 5 or a little lower.

You can use a few small amount of Muriatic acid to lower the DKH of your new salt water. There is a thread in the chemistry forum about how to reduce your ALK. Also lowering your salinity to 1.025 will help a little.

Well i haven't check my dkh of my tap water and i don't wanna use my saltwater dkh test kit on that, not sure how accurate it is, outputs of the ro are good, that was the first thing i checked lol. Yes that is what i did i use muriatic acid in a 5 gallon water change, my dkh tested 11 and after 3.6mls of muriatic acid it went down to 8
...the ph drop a lot so i left it overnight with a powerhead to raise it ,today it was 7.8 which is pretty close to what my tank is, all in all it went well. Also i ordered a tds meter so i will check where my ro/di is sitting at, i'm pretty sure the filters are bad, haven't changed them in a while:headwally:

 

[gaby_scan]

Testing dKH of RODI water using a saltwater test kit might not give a "valid" result.

Testing TDS of your RODI is absolutely valid. TDS of water from your RODI water should be close to zero (or actually zero if you run a DI stage). If you never change the DI resin, I believe it can leak ions into the output water. Perhaps thats your problem.

-droog

Tds on the way, yes haven't changed anything in a while. Pretty sure that is the culprit here.

 

[droog]

Just curious... what happened in the end?

-droog

 

[gaby_scan]

Just curious... what happened in the end?

-droog

Hi, well i bought the tds meter and when i tested the water going out of my ro it was reading 78tds(i know my fault). So I ordered a set of new filters, gac,etc and my reading now is 3,4tds. Still have to buy the di to get 0 but my alkalinity problem got solved. I did a couple of water changes until it dropped to 8-9dkh and it has been staying there.

 

[droog]

Cool, glad it's fixed. I didn't realize dirty source water could have such an impact on dKH.

Not as bad as my mistake... I got the RO lines mixed up and used the reject water instead of the clean water. The algae in my tank had a field day!

-droog