Alkalinity Going Up Instead of Down

[beehive124]

It is my understanding that corals use alkalinty and other elements to make their skeletons. So, in theory the alkalinity in my tank should be going down due to my corals absorbing it, right? I tested my water two days ago and the alk was 8.7 and today it is 8.9. Is there any explanation for this? I’m using a hanna checker and the accuracy is .01 ppm I believe, so maybe it’s the checker, but I’m not sure.

 

[MnFish1]

1. You're using dKH (8.7 and 8.9) but you're using ppm for the 'accuracy'.
2. Assuming you're using the dKH Hanna alkalinity checker. the accuracy is +- 0.1 dKH. (not 0.01 ppm)
3. This suggests to me that the 2 results are basically the same (i.e. they both could actually be 8.8)
4. Alkalinity can vary based on time of day and multiple other factors (nitrate metabolism, etc) so its best to measure alkalinity at the same time of day.

I.e. I wouldn't be concerned unless its a daily uptrend (or every couple days. If you're dosing alkalinity, you may need to adjust it if thats the case - depending on where you want your alkalinity to be

 

[beehive124]

Thank you very much! Sometimes I get overly worried about my tank

 

[WestonNanos]

Thank you very much! Sometimes I get overly worried about my tank

Dont we all... lol the DKH hanna checker has an aaccuracy of + or - .3 DKH just for clarification (so you are in a range from 8.4-9.2). Are you dosing anything ? Also to note, sometimes if a change in things like lighting or flow irritates a coral it could stall coral growth, thus decreasing ALK consumed, thus making your dosing out pace your consumption.

 

[beehive124]

Dont we all... lol the DKH hanna checker has an aaccuracy of + or - .3 DKH just for clarification (so you are in a range from 8.4-9.2). Are you dosing anything ? Also to note, sometimes if a change in things like lighting or flow irritates a coral it could stall coral growth, thus decreasing ALK consumed, thus making your dosing out pace your consumption.

I’m not dosing anything. My corals aren’t quite big enough yet

 

[reefwiser]

If alk is going up in your tank then your corals are not growing. An are not taking up the calcium in the water.

 

[WestonNanos]

If alk is going up in your tank then your corals are not growing. An are not taking up the calcium in the water.

Correct, Alk should be decreasing due to coral demand, But , as he stated he does not have very much coral, and the test results are within the margin of error

 

[Randy Holmes-Farley Verified Community Expert]

There are reasons for alk to rise (nitrate declining, slow dissolution of rock and sand, etc.), but I would not focus on them until you track the alk longer.

 

[beehive124]

Thank you!