Polyp super extention after Calcium, Strontium, iodine additive

[Casperson]

Hi Randy,
Twice weekly I add 15ml strontium, 15ml calcium cloride, 15ml calcium gluconate, 2.5ml iodine.(All follow manufactures recommendations:Seachem products.) I do this within minutes of each other. I've noticed within minutes after, my sarcophyton(leather) and hammer coral extend their polyps in an extreme fashion. The ends of the sarco's polyps spread very wide and then slowly retract back in. The hammer coral seems to fill it self and balloons up as if it is filling itself with water. Looks bloated. This only lasts about 15 minutes, Then back to normal. Any thoughts on what's happening here? Should I stop the additions? All other corals don't show any difference when I do this. All coral are very healthy. I have a 55gal. tank with total water volume with ref./sump 75gal. so I know I'm not over- dosing my Strontium, calcium and iodine. I dose calcium because my Kalkwasser supplement doesn't seem to get me over 375ppm cal. PH 8.2 Alk 12dkh

Thanks,
Tom C

 

[Horace]

Just a FYI... Normal seawater is 6-8dkh. Your running your alk a bit high IMO. 375-400ppm is good for calcium as well. Anything over 400 is pretty much a waste anyway

 

[Randy Holmes-Farley]

Are you adding calcium gluconate or calcium polygluconate?

 

[Casperson]

Hi Randy,
Calcium gluconate, Seachem product. Quite sure there's not polygluconate in it? hmm?
Some responses have said I'm adding them too close together, time wise? I add them one after the other in my sump/refugium.

Tom C.

 

[Randy Holmes-Farley]

Seachem's calcium product "Reef Calcium" is polygluconate:

http://www.seachem.com/products/product_pages/ReefCalcium.html

"Reef Calciumâ„¢ is a concentrated (50,000 mg/L) bioavailable polygluconate complexed calcium intended to maintain calcium in the reef aquarium without altering pH."

The polygluconate is unclear in terms of what it does. It may provide alkalinity. It may also be a carbon source for bacteria. I do not know if the polyp extension is an indication of something good, bad, or indifferent, but you might dose the calcium polygluconate, and each of those others, alone to see which one causes the effect.

 

[Casperson]

Thanks Randy,
I'll give that a try.

Tom

 

[Randy Holmes-Farley]

You're welcome.

Let us know what you find.

 

[Casperson]

HI Randy,
Just dosed polygluconate alone. Within 1-2 minutes I notice the polyp extension to occur in both the leather and hammer coral. The leather extends and then contracts, almost looking like its feeding itself from the water column. The hammer bloats up quite a a bit. These are two very healthy looking coral. I also note that these 2 corals are in the direct water flow from my sump return, Maybe receiving more concentrated amount then the rest of the tank. No other corals show any signs of change. hmm, As I write, I am noticing my xenia to be doing a similar action, still pulsing, but definitely more engorged looking.

Just a follow up,

Tom C.

 

[Randy Holmes-Farley]

Thanks, that's interesting to note. They might be feeding on the polygluconate, or are at least trying to, whether they can succeed or not. Sort of like me enjoying a diet Coke, even if it doesn't supply any sugar that my body thinks it is getting.