So, some time has passed... wanted to pick this back up.
Over the last year and change, I've struggled with water quality, especially pH, bounces in this tank. Smaller tank, OK, I'm a firm believer in larger tanks being more stable, but I've had 29g tanks that were more stable than this one has been. pH tended low, leading me to keep doing things to raise it, probably worsening the instability. Calc/Alk bounced all over the place. Growth rates of SPS corals was poor, though colors have remained strong.
A month ago, I made some changes. First, I changed out my Eshopps R100 sump/refugeum for an Eshopps RS100 sump. Lost the refugeum, along with several impossible to reach (or clean) areas in the system. Those water channels look great, until they're full of crud, and you can't get to them. Add in a small, center-rear return pump compartment, it was just not an ideal design for my purposes.
2nd, I went from a submersible Ehiem pump to a similar flow rate Iwaki external pump. Mounted where I can get at it, with union ball valves on both sides... easy to service, quiet, and doesn't add heat to the tank.
3rd, I removed a cheap dosing pump, gravity fed ATO, and BRS 2part and went to a Tunze ATO with an inline Kalk reactor. A month later, I'm tracking a very steady pH of 8.3, and rock solid calcium and alkalinity readings.
I'm hoping more stable water conditions will lead to better growth rates. I'm really hoping that my slow growth rates are related to bouncing water quality, rather than lighting. I'll give it a few months, and see. If this doesn't do it, I'm going to switch out my Halo for a different light. Not sure which one yet... and I hate to do it at all. I love the look and form factor of the Halo. Still, if it's not doing the job, I'll change. I may hang a 250w DE halide pendant and be done with it. I _know_ growth will be good under halides, but I'll have to start dealing with heat problems that I've been trying to avoid. I don't want a canopy, so honestly, T5 is not going to work for me... I could go with another LED... the Hydra 26HD seems likely, but I'm not certain it would solve my problem... if, in fact, the problem is lighting, which I'm unconvinced of... yet.
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