strange acro die off

[sipe]

I have been keeping acros for 2 years now in a 75gal mixed tank with 35 gal refugium. They have grown exceptionally well with 1 inch frags becoming 8 inch large colonies. I routinely frag them for others.

Parameters have been SG. 1.026, Alk 3.5-5, Ca 300-500, undetectable phosphates and nitrates. I check levels monthly and use RODI water with Kalk to replenish. With some reef complete every 2 weeks.

I was surprised when a gorgeous red millepora started dying off at the base and the die off spread to every tip. I thought maybe since it was a newer piece about 4 months old something had happened. All my levels were fine except I found 2.5 of nitrates for the first time (may have been from mucking around in the refugium after a fish got caught in it). After a 20% water change back to undetectable levels.

Two weeks ago it happened again with a unidentified acro and then this week with a hyacinthus. Always at the base and working out to towards the tips. At least 8 other species of acro are doing well still. Nitrates are undetectable currently.

the tank was finally looking great. Any ideas what else to check?
My two cleaner shrimp did spontaneously die as well maybe i am not supplementing something?

thanks for any advice...

 

[tacocat]

I suspect stray electircal current or a faulty piece of equipment. Check your powerheads, pumps, and heaters.

 

[sipe]

wouldn't electrical current affect all the corals equally?


All the powerheads flow fine. Anything in particular I should look for?

Is that die off pattern normal central then outward? I have seen branches die off occasionally, but never this central pattern.

Are there parasite that can do this?

 

[impur]

Might check for AEFW. I was going thru the same thing and couldn't figure it out. Then one day i noticed the bite marks on a frag. They love milles.

 

[mntl]

Alk 3.5-5, Ca 300-500,

With alk, if you mean KH value in DKH then this very low, I am assuming you mean meq/L, in this case 3.5-5 meq/L is 9.7-14 DKH, this combined with a range of 300-500 cal is a huge swing!! 300cal is very low for acros and 500 is extremely high. An acceptable range (over-time) would be like 400-420 cal 3.5-3.7 meq/L (for example). I would start by getting these inline because even if they are not the issue, they are amplifying anything that is wrong, it is like adding stress on stress, it will make recovery much more difficult.

The reasons for acros dying=parameters are out of line and inconsistent or something other than this is irratating them and this is amplifying it.

Do you have any pics of the affected acros?

-john-

 

[sipe]

AEFW

Not sure what that means...
But no bites marks.

John,

I do not have photos of affected acro's yet.

Imagine a multi-branched green acro. The base has turned white like bleaching. The bleaching patterns follows the branchs one at a time all the way to the tip. This happens until the coral is completely dead and bleached. I have cut off a frag of one of the affected coral before before this spreading white got to it. Its like the zooxanthelles are dying off after something zaps the base. the branches are not dotted with bleaching areas, just a bleaching front so to speak.

I agree about the stress idea, but those parameters are over last 2 years. The last 3 months ALK (in Meq) was 3.0-3.5. Calcium has fluctuated 275-350. Last year I was able to maintain it in the 400-475 range, but added many more acro's with a higher a high calcium demand and it runs lower now. (Should get a CA reactor, but moving in 9 months and will upsize the tank so waiting until then to buy)

Thanks

 

[herefishyfishy2]

AEFW= acro eating flat worms= bad little critters