palys browning

What are your parameters?

Though the testable parameters are all within range, the tap water impurities at your house may be creating difficulty for coral, but I would bet that is not all. Problems are often caused by a combination of factors.

Together, we should be able to figure it out. If you can, please take us through everything, such as:
water change size and frequency,
what chemicals and supplements are being added (including if a water conditioner is added to the tap water,
what lights were used before the 250W MH and where they were positioned,
what Kelvin were the previous lights,
what pump is being used for water flow,
use of Activated Carbon(AC)?, PO4 remover media and frequency of use,
etc., etc.

AC is critical to tank health and helpful to coral color. I run a large bag at least 2 weeks/month or a smaller amount continuously.

A full tank pic and a pic of the Refugium would also help us help you.

If the temp is at 79, how often does it rise over 80, how low does it go and when? Temperature can fluctuate daily between 70 to 80 with no bad effects, but if it exceeds 80 daily, that can be a problem. I keep my system at 73-75 so that in the afternoon when the sun warms the room towards 80 the water can rise to 79 but never exceeds 80. If it gets close to 80 I start up a small fan pointed directly at the water.

Looking again at the pic, the last thing that comes to mind is the water flow. It looks kind of like there may not be enough flow. This means the coral are not able to get rid of waste and get fresh water for food and breathing.

Mahalo,
Mark


Edited by Mark Peterson - May 06 2014 at 5:49pm

oh and the temp varies from 77 in the morning to 79 - 80 max in the late afternoon when its the hottest and the lights are heating the most, then it will cool off to 78 after about an hour when the lights go off and cool to 77 overnight. So a very small fluctuation through the day.

I would have said that 250 watts of MH light was too bright but the pic does not give me that impression. I have used an old 400W 20K MH bulb positioned less than 1' over a shallow coral frag tank without problem. Old bulbs emit less light. The lack of blue in the pic makes me believe that this is the old MH bulb that came with the fixture, right? Blue fades as the bulb ages. Since you brought it up, I believe it would be good to raise the new light a little more and/or reduce the photoperiod. Have you heard of Light Acclimation? Too much light too quickly can cause "sunburn".

It's quite possible that the Zoanthids, being only 3 inches underwater, were burned under the LED lights. Some LED's don't look that bright to our eyes, but they are bright enough in the right spectral wavelengths to give coral a sunburn. (A change in light spectrum occurs when switching lights which can also lead to sunburning.)

AC is a must for every reef tank. It removes toxic chemicals that nothing else, except water changes, can remove. What is the recommended amount being used and from where did that recommendation come?

Newly mixed saltwater is significantly different than the Live Water in an existing reef tank. It's not just the typical parameters we speak of, rather it's things we don't test, like the bacteria count and single-celled algae count in the existing tank water, that significantly impact coral health. Live Water is a good thing. I always suggest 10% monthly water changes. Keeping the water conditions fairly constant is important. It's revealing to note how Nick801 has not changed water since his tank was set up. Also note that the tank was started by filling with tap water 3+ months ago. See his post yesterday here: http://utahreefs.com/forum/forum_posts.asp?TID=69030&PID=564761&title=nicks-300dd#564761

Regarding the new pump, some would say that our marine aquariums cannot have too much flow, as compared to the ocean.

What is the recommended amount of phyto being used, what brand and how quickly does the water clear?

Assuming the SPS coral are doing well, tap water would definitely not be the problem for the SPS. If it were, the SPS coral would be the first to show signs. Also, SPS eat up Alkalinity.

Your description of the Zoanthids makes me think of chemical and radiation burning. I'm inclined to believe the Zoanthid browning and skin sloughing problem is caused by the combination of Sunburn and Alk being at/above their Alk threshold.

Aloha


Edited by Mark Peterson - May 07 2014 at 8:58am

actually this is a brand new pheonix 14k bulb, was only fired once before i got the system. the camera darkened the image alot i believe. the light is quite bright and lights up my room better than direct sunlight..
i am using 1 cup AC per 20 gallons, which is what my system is. im also using about 5ml phyto that was both home grown and bought online by a private seller, hopefully a combination of a coral dip, reducing alk and allowing them to acclimate to light will solve the problem. i run about an 11 hr period on the mh, is that too much? should i reduce it to about 9 hrs?