[Delphinus]

The hair algae and small patches of cyano in the tank tell me that nitrate is likely not exactly zero, despite the lack of a colour formation in the test kit (last tested using Elos). I had a nitrate meter at one point but the probes only last about a year and I haven't ponied up the $200 to replace it again (I replaced it once already .. I can't seem to pull the trigger on ordering a replacement).

There is an HRV in the house, temperature seems to remain steady at 26c, salinity is targetted to be maintained at 1.025 although maintaining the magnesium seems to push SG upwards to 1.026 lately .. I don't know if I should lower it to compensate or not. I've just been using IO for salt this year.

Copper, I didn't think of that, but seems prudent to rule it out or confirm if that is indeed the case.

I can't rule out that I might have simply overdosed, what is weird is that up until two weeks ago it was dropping and I was needing to increase the dosing schedule. It does make me wonder if I've simply let the see-saw out of balance with the Calcium being too low. Usually the rookie mistake is testing Calcium and thinking "everything is fine" but letting Alk get too low, maybe I've done the opposite and gotten tracked Alk too obsessively while getting too lax on Calcium.

I can up the Calcium dosing and see how things go. "Back in the day" I always kept my targets at 4.0meq/l (or 11ish dKH) and 400 ppm Ca, I liked how the one number was just the other number with the decimal point moved twice, it was an easy way to remember if the two params were in balance with each other, but I find the whole zeovit/Korallen-Zucht prescriptions to back away from higher numbers and it makes my head swim at times. Polyp extension and colours are great under this system, growth just isn't there in my opinion when I see what other tanks are capable of in a 6 or 12 month period, mine just isn't there.

Plus the hair algae over the rocks .. It seems as if the rock has nutrients bound within (it was all dry rock to begin with, and this particular tank is only about 10 months in so it's possible it simply hasn't matured enough yet).