Crumbling sps corals

[THEmarineman]

Hi
I have a strange problem with some of my SPS corals.
The corals are in good vibrant colors and the polyps are well open and extended.
The problem is that if I accidentally touch one of them it will easily break down and even crumble!

My system is on low nutrient regime based on vodka carbon injection.
Ca = 430
Mg= 1300
Alk= 7.5

Thanks

 

[Poorcollegereef]

Do you have an idea of what types of SPS you have. Some of my deepwater acros are very delicate. Others are touch and break easily while others are very tough and will even stand a night out of the tank (by accident)

 

[THEmarineman]

Hi
At the beginning I thought it was only my deepwater across. But then the green slimmer
Had the same problem…..

 

[BlastoEric1589]

your alk is a bit low but i dont know if that would effect the strength of their skeleton.

ive seen rose monti under 250W 10K grow extremely rapidly, and as a result, develope very little rigid strength and would break to the touch.

on the other hand, my green monti grows very slow, and this allows it to develope a very thick, strong skeletal structure

so IMO its related to your growth rates and thats linked to your lighting intensity

 

[Dizzle63]

I have always heard that low alk will make SPS "mushy".

 

[BlastoEric1589]

sounds plausible.

alk is the measurement of the carbonate hardness or "saturation" of the water, and many of the elements that contribute to the alk are essential parts of the skeletal structure.

so im guessing that if the alk is low, than the percentage of available skeleton building minerals and elements will suffer, and thus make your SPS mushy or crumbly or just plain weak...

im no marine chemist though...

this might be a question for the chemistry forum... whether or not skeleton strength is linked to alk...????????????

 

[jmadison]

strontium and molybdenum i've heard lead to harder corals, but slower growth rates. hope that helps

 

[HighlandReefer]

If your pH is lower than 7.8, the calcium carbonate in your corals may to start to dissolve.

 

[BlastoEric1589]

highland is right... a pH drop will disrupt the covalent bonds in the skeleton and cause the calcium carbonate to dissolve...

its based on a principle i learned in a certification program for work but it was targetting calcium scale in swimming pools.

its the same idea though. this definately seems to be heading towards a low pH and/or KH problem

 

[THEmarineman]

ph 8.3

 

[teesquare]

I know this sounds "out- there", but if you have a low range volt/ohm meter - check the tank for small "stray" electrical current.

It has been a number of years ago.... but seems that there was discussion about this...................

T

 

[THEmarineman]

Thanks, I'll just fo that.....

 

[ctenophors rule]

all that the strontium does is retard coral growth, that is why those corals are bushier, their outward growth is slowed

 

[teesquare]

Uh...well, I seem to find that the "bushy-ness" ( if you are referring to shorter thicker type of growth) has more to do with currents and water movement - in my my tanks.
I you don't have much water currents, corals often grow sort of "spindly", thinner branches.
All of this takes exception to some of the Prostrata - which can be more squat, and thicker branches, and Anaacrpora which grow thin long branches anyway
T

 

[BlastoEric1589]

im sticking with a low KH.

that sounds like the best explaination right now

 

[teesquare]

It does seem the most likely...............
T

 

[BlastoEric1589]

i mean, with the information given, thats all that seems to be out of place.

IDK, some tanks just dont do well with certain inhabitants.

some people can grow SPS like weeds, others struggle... its kindfa hit or miss with some of this stuff, and sometimes the health of a coral is sorta beyond our control.

our tanks will never perfectly replicate the ocean, so theres always gunna be difficult specimens... who knows... maybe its the KH, maybe the corals are just suicidal...

 

[teesquare]

Well... I tend to think more critically about problems like this, and look for an analytical method to do some problem solving.
1. Were the records to indicate what the tank perameters have been?
2. Any changes, showing a trend?
3.What changes in maintenance, if any?
4.Any changes in additives?

And, there may be other questions that need to be asked..........
T

 

[THEmarineman]

Hello

Water parameters were and are still rock solid and satiable!
Few changes where made in a few weeks' period of time:
- Changing skimmer from Deltec apf 600 to ap701.
- Changing lighting fixture from 7*54W t5 to 2*250w mh+ 4 t5 54w. the change was very carefully including slowly lowering the fixture and extending slowly the light hours.
- Started using ESV B-ionic with dosing pump.
- Start feeding with "coral Frenzy " instead of Kent liquid food


Thanks