Alk rising on its own

[BuddyVanDoodle]

My alk was sitting steady and 8.5 and has been steadily rising for about two weeks now. I had kalk set up on a doser for about a month and then one day I noticed the alk rising so I cut that off and it’s still going up. My nitrates have been very low to undetectable. I read that if the get over 50 and then come back down really quick that can raise them, but they’ve been pretty much undetectable and there is no algae in the tank to be using it. All my sps was growing great until this happened and I can’t figure out what I could be doing wrong. Only other thing I was dosing was brightwell coral amino but I haven’t done that for a few days and it’s still rising

 

[lmm1967]

What is your CA level doing?

 

[Randy Holmes-Farley]

How much of a rise over 2 weeks are we talking about?

Water changes can certainly boost it, as can slow dissolution of sand and live rock, and even calcium carbonate sand in the GI tracts of organisms.

 

[BuddyVanDoodle]

It’s not rising fast, about .6 in two weeks. I’ve only done one small water change in about two months. Phosphates and nitrates stay low. I forgot to mention I also dose nopox about 5 ml a day in 100 gallon system. If it is the sand bed would a water change with a small sand vacuum do anything?

 

[Randy Holmes-Farley]

It’s not rising fast, about .6 in two weeks. I’ve only done one small water change in about two months. Phosphates and nitrates stay low. I forgot to mention I also dose nopox about 5 ml a day in 100 gallon system. If it is the sand bed would a water change with a small sand vacuum do anything?

That is a very slow rise. Vacuuming the sand might make it better (less organics to degrade and lower pH), but might make it worse (releasing) the dissolved material). The Brightwell product may also boost alk a but, depending on how they formulate it.

 

[BuddyVanDoodle]

What is your CA level doing?

calcium is kind of low at 400 . Used Red Sea kit

 

[Randy Holmes-Farley]

calcium is kind of low at 400 . Used Red Sea kit

At that alk change (0.6 dKH in 2 weeks), it will never move that you can see.

 

[BuddyVanDoodle]

So go for sand vacuum or is there something else I can do

 

[Randy Holmes-Farley]

So go for sand vacuum or is there something else I can do

Water changes with a low alk mix, or very slow additions of an acid to the tank, such as sodium bisulfate.

 

[BuddyVanDoodle]

@Randy Holmes-Farley I did the water change and vacuumed the sand and it worked. My alk was slowly going down from 10.something down to 8.9 my goal was 8.5. But then it started rising again. It went to about 9.3 and stayed there ever since. I was losing about .1 dkh a day. My question is could aiptasia x make it rise ? I’m no chemist but I saw something about sodium in it so I was wondering if that could have something to do with it. I did use it right around the time the dkh went back up

 

[SliceGolfer]

Exactly what I was going to ask. I use F-Aiptasia and notice a rise in pH and DKH immediately following. As the products are likely kalk based, it makes sense.

 

[Randy Holmes-Farley]

yes, it will raise alk and pH a bit. The MSDS says it contains calcium chloride and sodium hydroxide. It is the latter that boosts alk and pH.