SPS'ers that use Randy's 2 part

[Redfish]

Yes, I do have a very thin sand bed. Probably no more than about 1" or so anywhere.

Would you speculate that it is part of my alkalinity consumption?

I guess it is possible, but I treat it kind of like Steve Weast. I just don't disturb all of it all of the time.

 

[Redfish]

I will also add that I see a fairly wide swing in consumption of both parts as my tank temperature swings. I do not use or need a chiller. My tank averages about 72-74 in the winter and consumption goes way, way down. In the summer the tank runs about 77-79 and consumption goes way up.

I also experimented with my MH lighting schedule for a while. I have always run the MH (AB10k and now PH14k) about 6 hours per day. I tried going to 8-9 hours per day. My consumption went up but I did not notice a growth rate increase. That was a little strange. I didn't think my colors improved either so I backed down to 6 hours per day again.

Another item of note is my change from AB10k to PH14k and coralline alage. The AB bulbs suppressed coralline algae growth. The Pheonix bulbs have supported a massive growth of coralline algae. I believe this a substantial amount of my consumption.