Alkalinity swing destroyed sponges!

[Ocelaris]

So I've got my 2 part dosing down with brs dosing pumps and alk has been steady around 10.5 for some time, mag and calcium also in good range, 1450 and 450 respectively, so I thought I'd move the alk up a tad and bumped it up in one shot to about 11.3 and this morning my sponges which were growing nicely had turned into these spikey messes. Oops! They have done that before, and they'll grow back, but it's a good indicator when things are not stable!

 

[Ocelaris]

Wish I had some shots before, but here's the aftermath

 

[Randy Holmes-Farley]

How much of a swing? This result seems unlikely to me to be caused by alkalinity.

 

[Ocelaris]

I was 90ml of soda ash solution, probably only 0.8 dkh at max, but I didn't test immediately, but I will check again tonight.

It's just wierd because I have seen them do this before and don't really know what they are made if, but I thought it was silicate?

They usually rebound in a few weeks, but never get very large. Just was wondering the chemistry if sponges.

 

[Ocelaris]

Alkalinity was just 10.7 today, the original 11.3 was a guesstimate by the brs calculator. I dose around 100ml of alk and Calc each day, which is roughly stable, so either I precipitated it out or vastly underestimated how much I need over the course of the day.

I just wanted to put this thread out there in case anyone else runs across this phenomenon. It may have nothing to do with the alk bump, but I can't really attribute it to anything else.

 

[Randy Holmes-Farley]

Yes, that is not enough to cause the issues you saw, but I don't know what did. Sorry about it the loss.

 

[Ocelaris]

And just like that they're back, albeit not fully at their former size, but close. It's amazing how they can reconfigure themselves in the few days but don't grow any larger than that usually. This is probably from Florida live rock that the previous owner had. And these things survived some nasty cycling as well.

 

[skim]

Did you feed or have a Temp fluctuation. That is strange, I wonder if a Snail was doing its rounds over top of them. almost looks like some type of a defensive pose or stance.

 

[Ocelaris]

You know, the pictures are from two different side of the tank, so I don't think it could have been a hermit or snail. It's like they reconfigured themselves, closed up and now are back open.

Apex controls the Temps within 77-78 degrees. Food was the normal mysis and some pellets. It could be a normal reorganization, but just strange across the 5 foot tank the same sponges did the same thing. PH was between 8.15 and 8.25 as usual with that 10ish dkh.

 

[skim]

Could also be a Fish taking tiny nibbles, my Moorish Idol did that when I first got him and now does not touch them, but he is feed well. It just looks so much like a defensive mode, defalting and creating what looks to be spikes.

 

[Ocelaris]

Could be, I've seen my yellow tang nibble on the yellow ones, but never seen him touch the pink ones. I'll have to keep an eye out!