Coral Bleaching -Help!

[beachsidereefer]

Hi All,

Hopefully you call can help me as I'm all out of ideas what to check.

220 gallons total volume
MH and LED fixtures. skimmer, GFO, carbon. I auto dose ALK, CALC and Lime water. All equipment appears to be functioning as expected.

tested today
PH 8.1
salinty 35 PPT
Calcium 382
ALK 8.9
Nitrates 2-5 PPM
Phosphates 0.03 PPM
temp controlled for 79-81 degrees with chiller.


Two weeks ago i noticed a tip starting to bleach (see pic below) from a colony that's been growing steadily for 5 months. The bleaching started small and has now spread all over. What's worse is I've noticed some of the other stony corals now showing white tips. All my softies, fish, inverts seem happy and no signs of stress. One week ago I did a 20% water change which is part of my monthly maint. schedule. The only change I made two weeks ago is I added one extra hour to MH and LED time schedule so now all fixtures run at peak intensity for 8 hours.

to see if I have flat worms eating the coral I took the sample you see in the pic and added coral dip and a drop of eXit to the water. I checked it after 30 minutes and I didn't see any pests drop off the coral.

so now I"m out of ideas except could one extra hour of peak light intensity cause this bleaching problem or is this a red herring?

 

[Russ265]

alk too high imo.

get another alk test kit

 

[beachsidereefer]

alk too high imo.

get another alk test kit

not sure I understand what you are saying. is my alk to high in relation to my calcium level?

I use Salifert ALK test kit which I thought is pretty good. is there another brand you recommend?

 

[beachsidereefer]

also I see I forgot to mention MG which tested at ~1400

 

[Russ265]

not sure I understand what you are saying. is my alk to high in relation to my calcium level?

I use Salifert ALK test kit which I thought is pretty good. is there another brand you recommend?

alk too high in relation to your nutrient level.
id try 7.5-8 unless nitrates start climbing 5-10.

salifert has burned me before. i use red sea pro kits

 

[Anirban]

I will go with @Russ265 . Either you lower your alkali to 7.5-8 range or you bring up your nutrient level. You can take out the carbon for sometime and put less light intensity.

 

[beachsidereefer]

thanks all for the tips. I'm going to disable my ALK doser and test daily till it drops to 7.5- 8 and turn off the carbon reactor.

 

[beachsidereefer]

figured out what was wrong. My calcium was sky high.... Here's the details.

https://www.reef2reef.com/threads/wildly-different-results-when-testing-calcium.249035/#post-2928327

 

[Russ265]

figured out what was wrong. My calcium was sky high.... Here's the details.

https://www.reef2reef.com/threads/wildly-different-results-when-testing-calcium.249035/#post-2928327

while ive heard of sky high calcium driving alk down, ive never heard of it burning tips.

my tank is currently at 465 ppm calcium.

anyway... it does seem something is out of balance. i would suggest a water change.

 

[beachsidereefer]

while ive heard of sky high calcium driving alk down, ive never heard of it burning tips.

my tank is currently at 465 ppm calcium.

anyway... it does seem something is out of balance. i would suggest a water change.

it's all I have to go on right now. I believe the only thing left would be some type of unknown toxin has entered the water that kills stony corals.

 

[DeniseAndy]

What softies are in the tank?

 

[beachsidereefer]

looks like I'm good now on CA at 430 and ALK at 8.1. I'm planning letting CA fall to 420 before I stabilize it.

is there anything I can do for the damaged corals or do I just let nature take it's course and see if they bounce back?

 

[Perry]

If you still have tissue on the corals then hopefully they will recover. Just make sure and keep things relatively stable with regards to alk. I agree that a higher alk with lower nutrients tends to cause issues. Good luck! :)

 

[beachsidereefer]

If you still have tissue on the corals then hopefully they will recover. Just make sure and keep things relatively stable with regards to alk. I agree that a higher alk with lower nutrients tends to cause issues. Good luck! :)

fingers crossed they come back. My ALK is now in the low 7's so going to dial in the dosers to keep it in the 7-8 range and CAL around 420-430.

 

[beachsidereefer]

thought I would provide an update in case anyone is keeping up on this thread.

I've since switched to a red sea CA test kit. my ALK is holding steady around 7.5 to 8 and CA around 410. Most importantly I'm seeing recovery of the corals that bleached and only one small colony totally bleached out and died. I'm cautiously optimistic that I'm back on track since I'm seeing recovery of the tissue.

 

[dwebb1031]

You could even get the alk a bit higher I run mine around 10

 

[dwebb1031]

I have a lot of montis which rob all the alk from my sticks so I through in a bit extra for them

 

[beachsidereefer]

I have a lot of montis which rob all the alk from my sticks so I through in a bit extra for them

My tank stays pretty low on nitrates and phosphates so the advice I've gotten is to keep it in the 7-8 range.

 

[recess62]

Will someone please explain the relationship between alk and nutrients. I presently keep my alk at 9-10 with nitrates 2-5 and phosphate around .14. I do not have and sps. The tank has LPS softies and Zoas

 

[beachsidereefer]

Will someone please explain the relationship between alk and nutrients. I presently keep my alk at 9-10 with nitrates 2-5 and phosphate around .14. I do not have and sps. The tank has LPS softies and Zoas

wish I had a answer but I don't understand the science behind it. My gut feelings are I'm going to go with the lower ALK for now and see what type of results I get. If after 6 months I'm not happy I'll raise it to 9-10 and see what happens.