Hard to believe, but this tank has been running for a year now...
Comparing it to my first tank, which was a biocube 14, it has been easier and the ability to do more things with it has been nice. But, I've still had the same issue of low alk. The past few weeks, the system has been running with an Alk of 5.5-6.0 dKH. Im not too worried because everything looks amazing, except for my acans (which are barely holding on), but with I'd like to get the alk higher for stability purposes. Because I had this issue with the last tank, I looked at both systems to find the common denominator that may be causing it. The only one I came up with was the salt mix, which is Oceanic. I like it for the high cal and mag, but I remember it having low Alk. So, before I changed to a different salt mix, I decided to do an experiment.
I took 2 buckets and filled them with 5 gallons of RO water.
Bucket 1 Bucket 2
S/G 1.025 1.0255
Temp 76 76
(F)
pH 8.2 8.2
Cal 575 585
Mag 1275 1305
Alk 10.05 10.4
(dKH)
Honestly, the Alk surprised me. I was expecting it to be much lower.
After starting a dose of 1/2 a tsp of Reef Builder every afternoon and adding a refugium to the sump (the light turns on when the main system's light is off), I have been able to get the Alk to 9.3 dKH. Will it stay, who knows....
Here are my current tank levels:
S/G 1.025
Temp 76
(F)
pH 8.2, I found that this had a huge swing from morning to night, like 7.8 in the morning and 8.2 by the afternoon. This was my motivation for a higher alk. Although everything looks great, it will all look that much better without the huge swing.
NH3 0.001
NO2 0.002
NO3 0.02
PO4 0.011
Cal 400
Mag 1305
Alk 9.3
(dKH)
I will have some pictures up within a few days...