How about Alk? 500ppm Ca seems a bit high, but I'm not sure if it's a bad thing...
If it is the toxins, you'll never get a definitive answer about when they wil go away. Water changes and carbon is about all you can do.
Alk Is perfect as wll Just measured it @ 7.7 DKH / 2.74 meq/L
Just remeasured Ca @ 490
Phos is 0 according to my test (salifert) and it was the LFS that gave me a# of .05<
Been doing 30 gallon changes (150 tank)w/ oceanic every 2 weeks
salinity .026 via refractometer
I run carbon regularly via a reactor and in sump ( 6-7cups)
I mean heck my water looks crystal clear and everything is beautiful in the tank (w/ the exceptioon of the Acro which as I stated is growing great just no color?)
Couple of things:
Zooxanthelae is brown so browning does not indicate the coral needs to replenish it; it has more when it browns . In some cases may have too much leading to the zooxanthelae breaking it's symbiotic role and becoming pathogenic as it overproduces oxygen which can harm the coral.
A coral may also brown up when it is stressed by interference with the calcification process from low alkalinity, calcium or high PO4; or when a metal toxin or allelopathic compound intereferes with normal processes. If your coral's are growing as noted this seems unlikely.
Terpenoids and other organics from leathers are long chains which may not have an affinity for gac, until they breakdown breakdown. So, if the leathers are gone for a couple of days with carbon running,I don't think left over toxins are a problem.
Color relates to lighting, and the development of protective pigments by the coral for the most part when other conditions are in place, including: the ability to calcify in steady alkalinity ,a good temperature range , steady sg,good flow , lighting, low PO4 and NO3,and so on.
If you think lingering leather toxins are a problem for some reason, you might want to run some purigen too since it may have an affinity for some organics that gac won't and vice versa. Poly filter could be useful too.
Personally if the coral isn't showing other signs of stress, I'd wait it out for a week or two and then if it was still brown , I'd get it into brighter light and flow. I'd probably recheck my : sg, alk ,PO4 and NO3 too.
TMZ thanks for jumping in...
I have extreme adequate lighting no doubt
1 400 watt 20 radium (via blueline ballast)
6 T5 w/ 4 Actinic (2 blue 2 purple) 2 14k superdaylight
12 Hi-Intensity LED fixtures
I was running all full blast for 8-9 hrs a/day but have recently(last 2 weeks) reduced to alternating cycles throughout the day 1st 2 hours warm up w/ LEDs then the Halide and 2 actinic T5 come on then 4 more T5's for like 2 hours (my high noon lighting) then all off but leds for last hour
ie: 3:30pm LED on
4:30pm Halide comes on w/ 2 actincs T5
7:30pm 4 T5's come on (14k superday & 2 more pink)
9:30pm 4 T5's Shut off
11:30pm Halide and 2 actinics off
12:00am Leds Off
Prior I had the lights all on @4 and all off @12:30 so its only been 2 weeks scaled back (and all bulbs are new or under their respectable lives.
So I think the lighting is optimum?
Is there a means by which I can measure the amt of Zooxanthelae in the system?? with the volume and frequency of water changes I just think that is highly unlikely but not ruling it out?
Additionally I run 2 vortech mp40W's mainly in reefcrest(yellow) in anti sync but regularly change the flow at least 1x p/day for at least 2 hours just to keep it changed up sometimes pulse long / or short or lagoonal but always back to crest
Temp is always 75-76' ( that may be a lil low?? ) but keeps nuisance algae from going bonkers
