Acropora Brown Tips and STN

[BigAsh]

Anyone have any thoughts on causes/remedies for this condition? The acros will do great for a month or two then start developing brown tips and then STN. 187 gallon tank is 16 months old. Alk steady at 8 dKh. Aquaforest 1, 2, 3 dosing regime. T5/LED hybrid lighting with 420 par 6" down at peak of day. Two Gyre XF250 at 100% OTS program (one at each end of the peninsula tank). Just added 2 MP40's at wall end (tons of flow now!). Thanks!

 

[Macdaddynick1]

Check your RO membrane first thing if your municipality is treating their water with chloramines and your membrane is old then look not further . If all is good there then check if you’ve had a ph dipped below 7.8 any night during last 2-3 weeks prior to this issue. Alk could cause similar problems as well

 

[jda]

That kind of tip death usually comes from high alk combined with really low nutrients, or LED burn. It does not look like alk burnt tips to me, this is usually in the areas of calcification that outgrows the tissue.

There is not much that you can do right now. Just arrest the STN and wait for them to recover. Then, you can snip the tips off and they can heal in a few weeks rather than the years that it will take for them to grow back over the old dead places.

The specs on your lighting (tube kind and count, LED kind and count) and a list of parameters will help people help you.

 

[BigAsh]

Thanks Mac and jda. My water district does use chloramines but my RO membranes are less than two years old and I'm using two carbon blocks designed to remove chloramines that are about 6 months old. RO output reads zero TDS. I'll do a chlorine test on the RO water though and may replace the carbon blocks with spares. I'm using an ATI Powermodule 48" with 8-54w tubes and 3-75w led clusters. The bulbs are 4 blue plus, 3 coral plus and 1 purple plus. The leds include blue, royal blue and red diodes. I'm planning to turn down (or off) the red diodes.

 

[jda]

I would turn all of the diodes off and see if it helps. The white ones are the biggest offenders for coral burn.

 

[BigAsh]

I think there's plenty of light without them so I'll give that a try. Thanks!

 

[BigAsh]

BTW, I forgot to list the white diodes. It does have those too.

 

[Reefltx]

Not sure lighting is your problem. I would look more into your water quality and maybe do a ICP to help spot anything that may be off.

 

[BigAsh]

Thanks. I have done two ICP tests in the last 9 months or so. Neither of them showed anything I thought was super critical. But on both, I was a little low on Iodine, Potassium and Strontium.

 

[BigAsh]

BTW, NO3 usually runs between 5 and 10ppm and PO4 between 0.03 and 0.06.

 

[Reefltx]

Thanks. I have done two ICP tests in the last 9 months or so. Neither of them showed anything I thought was super critical. But on both, I was a little low on Iodine, Potassium and Strontium.

I’ve been using the ATI hybrid since they released into market and have never had that problem. During peak, I have everything on 100%.

Have you inspected your sps closely for pest?

 

[BigAsh]

Thanks, that is encouraging! I have tried to look for pests and can't see anything. Last weekend I removed the coral at the top of the thread and dipped it in Polyp Lab Reef Primer which I've read is even more deadly to the bugs than Bayer. The dip seemed to make it a little worse but maybe it would have been anyway.

 

[BigAsh]

Thanks, that is encouraging! I have tried to look for pests and can't see anything. Last weekend I removed the coral at the top of the thread and dipped it in Polyp Lab Reef Primer which I've read is even more deadly to the bugs than Bayer. The dip seemed to make it a little worse but maybe it would have been anyway.

 

[BigAsh]

Thanks, that is encouraging! I have inspected for pests but haven't detected anything, particularly on the tips. Over the weekend, I removed the coral at the top of this thread and dipped it in Polyp Lab Reef Primer which is said to be more deadly to the bugs than Bayer! I didn't help and may have made it worse actually. I have read that there a bacterial infection that may cause this.

 

[pecan2phat]

Have you seen the BRS video on ammonia resulting from Chloramine? I think it was an RO/DI category but it's worth a look into regarding the removal process.

 

[BigAsh]

No, I missed that one but thanks, I'll check it out! Ammonia...yikes!

 

[Erick Armanii]

Has anyone come to figure out the reason for this? Some of my corals are having similar issues

 

[Badboy GP]

Did you find a solution? I have the same issue and have absolutely no idea..
Icp come back in range...

No real swings... my tank is over 2 years old.

 

[sculpin01]

Scrape off the brown stuff at the tips and look at it under a microscope. If that is unrevealing, dip the corals and look for parasites (Tegastes, AEFW). If that demonstrates nothing, consider an antibiotic dip.