Alkalinity Usage

[Joel B in FL]

I have been testing my alkalinity daily for the past three weeks or so now and for the first two and a half weeks my tank was using up about .2 DKH per 24 hour period, my goal is to keep my alk at 9 DKH. I try to test between 630 and 7pm each night so I can get a good usage for the day. The last couple of days though my alk usage has skyrocketed up to about .8 DKH per 24 hour period. The first night it dropped this much I thought I tested wrong and ended up testing four different times with samples from the sump and tank. When all four tests came back the same my next thought is maybe something happened to my 2 part solution and it was not providing the dosage that it needed to. So after I added the dosage I waited an hour and tested my tank again and the results were right on 9. So I knew I was dosing correctly however for three straight nights now my DKH has dropped .7, .8, and now .7 again tonight. My calcium usage through this time has remained steady as my tank pulls about 10 points per 24 hour period. Is it normal for a tank to jump in alk usage that much seemingly overnight?

Over the last week the only additional corals I have added are two small octospawn, a mini carpet anenome and a small rock anenome. I have not noticed any amazingly crazy growth in coral during that time either, and if it was growth driving the usage I would think the calcium usage would have went up as well.

All of my other parameters have remained the stable. The only change I have really made in the tank was I changed out my carbon and started using some Phosguard.

 

[BoneXriffic]

Im no scientist by any means, but my persinal experience is fornthe past 6months my calcium has been nearly identical in drop off where my alk fluctuates much more. I also burn alk much faster, and dose my alk part of the 2 part twice as much. I know this wasnt much help, just sharing experience

 

[njtiger aquariums]

Like @BoneXriffic I am no scientist. Hows your pH been? I noticed when my pH raise my alkalinity lower. Now there might be more factors in play there and I only test weekly right now.

 

[Joel B in FL]

Like @BoneXriffic I am no scientist. Hows your pH been? I noticed when my pH raise my alkalinity lower. Now there might be more factors in play there and I only test weekly right now.

My PH has been stable right about 8.0. I realize that's a little low but I live in central Florida and opening doors this time of year is not very realistic. I am going to hook a co2 scrubber to my skimmer to see if that will help with my PH. I also use soda ash for my 2 part as to help out with the PH some.

 

[Joel B in FL]

Im no scientist by any means, but my persinal experience is fornthe past 6months my calcium has been nearly identical in drop off where my alk fluctuates much more. I also burn alk much faster, and dose my alk part of the 2 part twice as much. I know this wasnt much help, just sharing experience

Thanks. I guess I just got worried since it was pretty consistent for a couple of weeks and then all of a sudden it took what I thought was a big drop.

How much does your tank use per day?

 

[BoneXriffic]

Thanks. I guess I just got worried since it was pretty consistent for a couple of weeks and then all of a sudden it took what I thought was a big drop.

How much does your tank use per day?

Usually between .5 and 1 per day

 

[Joel B in FL]

Okay I don't feel so bad then.