Need Duncan help =(

Well, of course we want to know the typical questions, such as tank parameters and how long you've had it.

 

Do you feed it?

Is there anything in your tank that might be irritating it? (My flame angel ate my colony)

How close is it to the lighting? What type of lighting.

The blenny could be irritating it enough for it not to open. Definitely check your alk, mine is not a fan of any deviation from 9.5dKH.

 

They're finicky, once they get messed with, they don't open for a while. If it's higher in your tank, chances are that the light is effecting it. Mine does not like direct lighting from the LEDs. Never had a problem under T5 or Halides with them, but the directness of the LEDs seem to irritate them.

OUCH!

That's dangerously low. When was the last time you did a water change, since you said you're due for one?

Before you bring your alk up, check your calcium.

 

(hopefully) simple explanation:

 

If alkalinity is low and calcium is high, add 1tbsp baking SODA to one quart of freshwater, stir hard or shake vigorously and pour in very slowly. It should raise alk by 1dKh. Adjust as needed, and test after every dose.

 

If alkalinity is low and calcium is low, add 2tbsp kalkwasser to 1g freshwater, stir/shake, wait two hours minimum to let impurities settle at the bottom then drip using an airline tube and gang valve in overnight at a rate of 3-4 drips per second. Test after every dose until you get the hang of it.

 

 

Your calcium has to be at the same levels as your alkalinity or else you didn't do anything. If you suddenly bring your alkalinity up, your calcium may dip way down. You'll need to check it either way.

 

Depends on what you are trying to accomplish. Is your calcium low too? Check your pH also. If your alkalinity is that low, I bet your pH is also low.

 

Why sure you could do a 50% water change and it would balance everything back out again. That would be simple enough. I just like to play around with chemicals. hehehe

 

I tell people to use kalkwasser... but me personally, I use Mrs. Wages Pickling Lime. I'de much rather pay $3 for 2 pounds of Mrs. Wages than $22 for 500g of commercial grade kalkwasser. The only reason that Mrs. Wages isn't regularly used is because there is an argument that Mrs. Wages contains a slightly higher phosphate content. I don't worry about it because an algae scrubber just eats it up.

 

Best bet is to order some kalkwasser online. I believe SWF.com might have some for sale. If you want to go that route...

I would suggest a water change before playing with adding buffers/chemicals since it's been so long since you did one.

It depends on what salt you're using. ESV can be used instantly, but the general rule is to let it sit/mix for 24 hours. That being said, I've used fresh mixed salt using AquaVitro Salinity, Coralife, Reef Crystals, Instant Ocean and Tropic Marin Pro all in less than 8 hours

If you got your alkalinity up a bit, that should have brought your pH up a little bit too. I wouldn't worry about making a water change before bed. First thing in the morning before work would be fine.

 

I don't do any water changes for 6 months to a year at a time. I play around with my tanks chemicals. I like to experiment a bit. lol.

 

What's your internal flow rate, and is any powerheads being pointed across the waters surface? That will bring pH up quite a bit. Also, do you use a refugium or algae scrubber on an opposite light schedule as your display? Having that would greatly benefit your system and stabilize your tanks pH.

 

Don't  you have some SPS corals? I bet they aren't too happy right now. :(

I had a bristletail filefish that mauled my Duncans.  They have been like yours for the last week or so, but seem to be coming out a little more each day since removing the filefish.

 

You definitely want to get the dkH up.  I'd do a water change.  Then either drip some kalk or use baking soda mixed with RO to get it up to around 9.