I had a mini-crash that I started appreciating in October of last year. Parameters were as ideal as I could test and I tested repeatedly and had LFS retest with similar results.
I first noticed a lack of polyp extension on my meteor cyphastrea. I was baffled and traveling but a slow downward trend really set in. I lost about four or five 2 year old colonies. Polyps retracted, then STN primarily at base but sometimes from tips. I also had receding tips on multiple colonies and loss of color--thats why no pictures for such a long time. Way too depressing.
I decided to do relatively large water changes but slowly. I have a 180 gallon tank with sump and refugium and lots of rock. So I did a series of twenty gallon water changes every day for 5 days consecutively. Waited a week and repeated and then repeated again. So over about a 5 or 6 weeks, I changed out about 300 gallons of water. (For those really clever mathematicians, it is not really 300 gallons because it was being diluted, etc. etc--but I manually lugged those 5 gallons containers in and out till I accomplished the task so in my mind, it really is 300 gallons). Wish I had a more elaborate system designed for water changes but it is just me and a bunch of jugs.
Anyway, I am finally seeing a turn around in both coloration and polyp extension. It seems like months for the positive change to become noticeable but probably more like just a couple months or so. Long way to go, not all colonies have recovered although most are showing improvements. Polyp extension on most is returning and color is starting to improve.
All of us can read our coral to some extent and I was seeing a slow decrease in vitality that I did not really believe until it became really really obvious. And yes, I was concerned about a giant tank crash.
I am hopeful that the improvement that I am seeing is a long term positive turn around. I don't know if I had not completed large enough water changes in the past and my water was deficient or polluted in some way that I could not measure.
So I am starting to take pictures once again. I am doing some redecorating of colonies. Since I lost a few colonies, I plan on moving some mature colonies to new locales--yes I understand that is a risky venture as well but its hard not to want to improve the esthetics when one has both the opportunity (real estate) and time simultaneously.
