Alkalinity keeps rising please help!

josh4107 · Mar 25, 2013

Hey everyone I am wondering if anyone could help me figure out why my alkalinity continues to rise on its own. I handy tested in a while and got a reading of 13.7dkh so I did a large water change and got it back down to 11.7 yesterday. Today it's back up to 12.04. I don't dose anything I have a 33 gallon with about 10+ gallons in the sump. I run a reef octopus 110, don't dose anything. Don't run carbon or gfo. Corrected if I'm wrong but isn't alk supposed to decrease over time instead of increase? Anyone have any suggestions?

josh4107 · Mar 25, 2013

My new water for a water changed measured 10.9 so it's high but not crazy high

ritter6788 · Mar 25, 2013

Not dosing anything at all? If it's not testing error then the salt mix either has a high alk or something added is causing it to rise.

Downbeach · Mar 25, 2013

Are you using any pH buffers, or tap water?

josh4107 · Mar 25, 2013

No ph buffers no additives. I'm using h2ocean salt like I said and it measured 10.7 on my Hanna meter so it is in acceptable range. What I don't understand is shouldn't my levels lower over a days period of time especially since I have lots of lps and a few sps? All my corals seems fine except for one of my chalices that is receeding a little. Could it be from over skimming? I'm just puzzled as to why it's rising not just why it's high.

josh4107 · Mar 25, 2013

Also I use a buckeye reef supply rodi unit just changed the membranes a couple months ago ...

kyle1284 · Mar 25, 2013

i ma guessing a testing error. try buying another test kit or have it tested at your LFS

josh4107 · Mar 25, 2013

I'm using a Hanna low range phosphate checker. And it may be a testing error but still, shouldn't my levels lower from reading to reading?

josh4107 · Mar 25, 2013

Sorry a Hanna alkalinty checker lol long day

josh4107 · Mar 25, 2013

Anyone have any possible explanations? I may just switch salts since the dkh is kind of high to begin with

aileen · Mar 25, 2013

A dkh of 10 is not that high. Either the test kit is bad or the salt is that way.

josh4107 · Mar 25, 2013

I would like to know more as to why my alk is rising on its own. Even if it was at 8 it shouldn't move up to 9 on its own without additives...

Reefing Madness · Mar 25, 2013

No reason for it to rise on its own. But your Salt mix being at 10, and you doing a Water change at that level, was not going to bring it any lower than it already is. Now, you can lower it yourself, you'll need to watch your PH. Use Muriatic Acid, this will lower it. Few MLS at a time will take it down.
And the reason it goes down is because the tank uses it, but if you have nothing in there using alot of it, it does not go down quickly.

josh4107 · Mar 26, 2013

Reefing Madness said:
No reason for it to rise on its own.
And the reason it goes down is because the tank uses it, but if you have nothing in there using alot of it, it does not go down quickly.

There has to be some sort of reason for the alk to be rising instead of falling when im not dosing anything any have plenty of lps and a few sps in the tank that should be using it up like I stated early. I think people are missing the point of my question also. Regardless of if i have a faulty hanna meter or not it shouldnt get a reading consistently higher than the day before... Ive decided to change salts since i just recently started using the h2ocean and didnt see this problem before. I always had an alkalinity of around 10-11 before with RC and no other problems so I'm going to switch back.

kyle1284 · Mar 26, 2013

The only thing that could be raising your alk would be your substrate. If you have crushed coral and your water is low enough in PH it may be dissolving the crushed coral releasing all and cal. But as stated earlier your PH does not get anywhere near the acidic point it needs to be.... Or everything would be dead

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fragmatic · Mar 26, 2013

You can bring it down by dosing calc... but I realize that does not explain the reason.

Reefing Madness · Mar 26, 2013

josh4107 said:
There has to be some sort of reason for the alk to be rising instead of falling when im not dosing anything any have plenty of lps and a few sps in the tank that should be using it up like I stated early. I think people are missing the point of my question also. Regardless of if i have a faulty hanna meter or not it shouldnt get a reading consistently higher than the day before... Ive decided to change salts since i just recently started using the h2ocean and didnt see this problem before. I always had an alkalinity of around 10-11 before with RC and no other problems so I'm going to switch back.

You've trouble shot it down to the Salt. Everyone else here including myself does not see any reason for your ALK to be rising at all. If the Salt your using has a bad batch and raises your ALk, then that would be an issue, but you said it was at 10, so there is no rhyme or reason to why. Got everyone looking here. For a test though, I'd dose it down to 9 and see what happens. And what ever you do, don't change any water or anything else before you test.

Nishar · Mar 28, 2018

Any update how you solve this problem? I’m facing same problem like you now. My alkalinity is 18dKH and I’m not dosing any buffer. My new salt mix alkalinity it 9dKH

Randy Holmes-Farley · Mar 28, 2018

Nishar said:
Any update how you solve this problem? I’m facing same problem like you now. My alkalinity is 18dKH and I’m not dosing any buffer. My new salt mix alkalinity it 9dKH

While I can advise on how to lower alkalinity, I think you need to look for the source, which would typically be artificial rock that wasn't fully cured before use.

Can you describe everything you add, and if you have artificial rock?

Do you use tap water?

Nishar · Mar 28, 2018

Randy Holmes-Farley said:
While I can advise on how to lower alkalinity, I think you need to look for the source, which would typically be artificial rock that wasn't fully cured before use.

Can you describe everything you add, and if you have artificial rock?

Do you use tap water?

Thanks for reply.

I do not have artificial life rock in my tank. I’m using RO (purchase from supermarket) though. In the past I do not have this issue where my KH between 8 and 9. My pH is 8.1 calcium 450, magnesium 1350. Whenever I change water around 20 to 30% KH drop to just 17, where before it was 19 initially. Now it increase to 18

I’m really surprise with this result where chemically it doesn’t makes sense. Where calcium and ph is in acceptable range...now I feel even I change water, it will be waste of my effort

Possible for a dying coral rock leach back carbonate hardness?

Appreciate for any help and suggestion.