KH to high... water changes only help for a few days????

[ChadOwens]

I have a 12g nano cube and am having a big problem with the KH constantly getting to high. I just tested it and its around 17dkh. I have been lowering it to around 12dkh with water changes every couple of days but in less than a week its back up again. Any ideas??? My PH is 8.2, Nitrate 0, Nitrite 0, Ammonia 0,
Calcium 420, Mg 1400, Sal 1.023, MH on for 10 hours/day.


Thanks

Chad

[Billybeau1]

[welcome]

What salt mix do you use and are you adding any pH buffers ?

[ChadOwens]

I stopped ph buffing since my last water change to emlinate that as the cause. I get water from the lfs.. I tested it and its fine.... kh is about 9dkh on lfs water.

[Billybeau1]

Well then the pH buffers were probably your cause. They are not a very good choice for reef tanks as the rise in pH is usually short lived and the alk just keeps climbing.

You should be ok now. :)

[bertoni]

The alkalinity should drop on its own now that it's no longer being added, most likely. Is there any DIY live rock in the tank? What is still being supplemented, if anything?

[ChadOwens]

Live rock is well established... its been in the tank for about a year.... the only thing I am putting in the tank is phytoplankton for the corals and frozen fish food.... also, some magnesium/ strontium occasionally. I havn't put any ph buffing in for over a week now and its still rising.... you think it will start to fall??? at what point will it be dangerouse to my corals?? 18dkh is pretty high isn't it??


Thanks

chad

[Billybeau1]

I'd give it a few more days and see if it starts to fall. Just keep an eye on your livestock.

BTW - what brand alk kit are you using ? You may want to get a second opinion on the test before doing anything drastic.

[ChadOwens]

Ya i thought that i might be crazy or that my test kit was bad so i had it double checked... im not crazy and my test kit is good :)


Chad

[bertoni]

I don't understand why alkalinity is rising if nothing's being dosed. That's very strange. What type of water is being used for topoff?