SPS colonies bleaching - Help me find the issue

[rowdyreefing]

Hey everyone,


Looking for some insight. I have a reef system with a total volume around 400 gallons. For the past year, I've been doing consistent 20% monthly water changes. Despite that, nitrates have slowly crept up and averaged around 20 ppm, with phosphates hovering around 0.15. Despite this, coral growth has been solid across both SPS and LPS.


A few months ago, I started lightly dosing vodka on and off to help manage nutrients. I hadn’t noticed much change until recently — I took a 3-week trip and accidentally left my protein skimmer off the entire time. When I returned, I tested and found PO4 at 0.22 and NO3 around 30.


About a week after that, I noticed several SPS colonies beginning to bleach. I’ve now lost 4 small colonies in a short span, and I’ve never experienced this kind of tissue loss before.


The only changes I can identify over the past couple months are:

• Occasional light vodka dosing
• Protein skimmer being off for 3 weeks
• One round of ChemiClean about 6 weeks ago for cyano

Could the elevated nutrients during the skimmer-off period have triggered instability or bacteria imbalances? Or maybe a delayed reaction from the ChemiClean?


Would appreciate any thoughts or similar experiences — trying to pinpoint the root cause before more damage is done.

Also, I am running lights at 25% right now in hopes of the bleached corals to come back.


Thanks in advance!

 

[Gumbies R Us]

Do you have photos of the corals?

 

[Dburr1014]

First off, I don't think your numbers were too bad pre-vacation.

I think you need to list parameters and check out other things in the tank like magnets and such just to rule them out.

I full tank Pic and pics of infected coral would be nice also.

Edit: my auto correct is being weird.
I corrected my first statement

 

[rowdyreefing]

Do you have photos of the corals?

When the lights come up some, I will try to get better photos, but here are two I could get

 

[gkprevite]

Why the skimmer off if I may ask? Having it off definitely can result in higher nutrients. They really weren’t too bad before. After turning the skimmer off they’re a little elevated

 

[Vested]

Sorry that's happening, hard to tell without more information but I don't think that those nutrients are a problem at all. I would look at anything that has changed first, protein skimmer being off is ab-normal for your tank but also don't see that causing major bleaching. There's a chance some bacteria went crazy without skimming but still dosing vodka.

I think the timing with you being gone for 3 weeks is interesting, would look more into everything that happened to the tank while you were gone. Always worth sending an ICP imo as well. For example did your tanks temp get high during those 3 weeks? Do you have an apex or something to see that data?

 

[rowdyreefing]

First off, I don't think your numbers were good pre-vacation.

I think you need to list parameters and check out other things in the tank like magnets and such just to rule them out.

I full tank Pic and pics of infected coral would be nice also.

ALk 7.9-8.4
Calc 430-460
Mag 1420-1450
^ these dont fluctuate much daily these are numbers over time.

I will get an updated tank pic when lights are on full.

Magnet- look for rust?

 

[rowdyreefing]

Sorry that's happening, hard to tell without more information but I don't think that those nutrients are a problem at all. I would look at anything that has changed first, protein skimmer being off is ab-normal for your tank but also don't see that causing major bleaching. There's a chance some bacteria went crazy without skimming but still dosing vodka.

I think the timing with you being gone for 3 weeks is interesting, would look more into everything that happened to the tank while you were gone. Always worth sending an ICP imo as well. For example did your tanks temp get high during those 3 weeks? Do you have an apex or something to see that data?

I travel for a living so tank is use to me being gone for those periods. I was an idiot and forgot the turn skimmer on after a WC.

I do have apex and did not notice any spikes.

I will do an ICP, but looking to avoid loosing anything else.

 

[Dburr1014]

ALk 7.9-8.4
Calc 430-460
Mag 1420-1450
^ these dont fluctuate much daily these are numbers over time.

I will get an updated tank pic when lights are on full.

Magnet- look for rust?

Yes, look for rusted, faulty equipment.

(I edited my first post) your numbers for nutrients are fine. Even elevated, maybe near the top end, but I don't think this is the reason. Do work SLOWLY on dropping them.
Get that skimmer back up and running.

Your big 3 numbers are perfect.

I don't like the look of your coral but do get better pics in white light. I'd like to see them.

 

[Vested]

I travel for a living so tank is use to me being gone for those periods. I was an idiot and forgot the turn skimmer on after a WC.

I do have apex and did not notice any spikes.

I will do an ICP, but looking to avoid loosing anything else.

It happens, keep things stable and try to reduce bacteria if you think that's what's happening (stop vodka dosing, turn on skimmer, uv if you have it). Id add fresh carbon just incase its some other weird contaminate.

I've seen a few acros bleach a week after chemiclean treatment once, have treated many different tanks dozens of times and never a problem but that one time couldn't explain it.

 

[rowdyreefing]

It happens, keep things stable and try to reduce bacteria if you think that's what's happening (stop vodka dosing, turn on skimmer, uv if you have it). Id add fresh carbon just incase its some other weird contaminate.

I've seen a few acros bleach a week after chemiclean treatment once, have treated many different tanks dozens of times and never a problem but that one time couldn't explain it.

Any chance they will come back?

I do have the largest pentair UV but bulb is old, do you think It is worth running?

Will add carbon. I was running vodka for a few months with no issues.

 

[Dburr1014]

It happens, keep things stable and try to reduce bacteria if you think that's what's happening (stop vodka dosing, turn on skimmer, uv if you have it). Id add fresh carbon just incase its some other weird contaminate.

I've seen a few acros bleach a week after chemiclean treatment once, have treated many different tanks dozens of times and never a problem but that one time couldn't explain it.

Solid advice!

 

[Catawba_Valley_Reef]

Was vodka still being dosed while you were gone? If so and the skimmer was off…then you had two things contributing to lowering your ph. Did the ph get excessively low during that time period ?

 

[rowdyreefing]

Was vodka still being dosed while you were gone? If so and the skimmer was off…then you had two things contributing to lowering your ph. Did the ph get excessively low during that time period ?

yes vodka was being dosed at a very low does.

I did not see any PH swings or any other swings

 

[Vested]

Any chance they will come back?

I do have the largest pentair UV but bulb is old, do you think It is worth running?

Will add carbon. I was running vodka for a few months with no issues.

Any acro that looks like that picture you sent is gone unfortunately, wish sticks were more forgiving. Yes if that's all you have I would still run it, make sure the sleeve is clean as well inside the unit. I love UV, run it 24/7

I've heard about bleaching events like this happening with vodka dosing, never personally done it. In my opinion I don't like the idea of it, too much potential to fuel bad bacteria.