Fragging of One Large Coral Causes Alk Swing?

[Les Poissons]

Yesterday I decided to frag a big Hollywood Stunner chalice that was outgrowing its space, blocking flow, and stinging too many other corals. I have a small tank, a Red Sea 170, and this coral had grown from 3/4” to about 9” across over the past year. Definitely the biggest coral in the tank, but I also have some other healthy and decent growers in the tank, including several montiporas, a softball-sized birdsnest, and a variety of other hard corals.

Alkalinity yesterday at noon was was 8.1. Today it is 8.6. I tossed some of the chalice and kept about 2/3 of it as frags. I’ve been dosing about 43ml of All For Reef daily to keep alk steady and I didn’t make any changes after yesterday.

Does it seem reasonable that one big coral in this tank, angry and sliming (and presumably not growing at all) after being fragged, could reduce the alkalinity demand that much to cause the 0.5 dkh swing in 24 hours, or should I be looking for something else?

pH is a bit lower than normal as well and my CO2 scrubber media is getting a little pale, so maybe the combination of the two?

 

[Troylee]

I’d say the combo of both.. we all know lower ph will drop alk,cal usage and that is a monster coral it could suck it quick in a small tank.?

 

[Les Poissons]

I’d say the combo of both.. we all know lower ph will drop alk,cal usage and that is a monster coral it could suck it quick in a small tank.?

Thanks. Replaced the CO2 media today and found the old stuff was not only pale but a little damp. Probably need to rig up an inline moisture trap. pH went right back up to normal with the new media.

Also cut back on dosing and will test alk frequently over the next few days to get things dialed back in.

Still a little surprised how quickly things changed, but that coral was definitely a beast for the tank and was still growing quickly.

 

[dakoop]

Ahh, good problems to have when things grow too much

 

[Katrina71]

That is massive! Wow

 

[Miami Reef]

What nutrient levels do you keep? Your growth rate is crazy!

 

[Les Poissons]

What nutrient levels do you keep? Your growth rate is crazy!

Parameters are usually around:
NO3: 6
PO4: .06
Ca: 430
Mg: 1420
Alk: 8

I feel like I feed reasonably heavily, but I struggle to get nutrients up. Sometimes I have to dose NO3 and PO4 to keep from bottoming out. For the corals specifically I feed reef roids about once a week and a few drops of K-Z Coral Vitalizer daily.

Also, the Hollywood Stunner has been sitting in about 150 PAR for most of the year.