My Shells Are Disappearing

[CageUK]

My spare hermits homes (shells to you and me) are slowly dissolving. It started off as a small hole in one of them but now there are quite large holes in at least two of them.
They have been in the tank for a few months and they are quite heavily encrusted in coralline. I'm assuming that the calciferous content of the shell is being assimilated into the salt water i.e. dissolving

Would this be a correct assumption or is there a marine critter that likes to munch on shells?

 

[SkiFletch]

Correct. Do you monitor calcium, alkalinity, magnesium, and/or pH on a regular basis?

 

[CageUK]

Correct. Do you monitor calcium, alkalinity, magnesium, and/or pH on a regular basis?

Yes Ski

I'm dosing to raise both mag and calc. Mag is at around 1140ppm (from 950ppm) and calc is around 415ppm. I have a current problem with low ph at the mo as posted on a separate thread a little while ago.

It is very difficult to raise these values. As soon as I start making progress I do a water change and undo a lot of the effort. I've resorted to leaving a longer period to water change. I'm afraid of overdosing so don't dose heavily as it is just a 58ltr nano and I know things could go horribly wrong if I'm not careful.

 

[1entra]

What salt are you currently using? It might be an idea to change your reef salt. I have a 45G tank that contains mostly LPS along with other corals and I have never dosed with calcium or magnesium. I use reef crystals salt and do a 15% water change every fortnight and find all my corals and livestock seem happy and healthy.

Might be an idea to change salt...

 

[CageUK]

I currently use Tropic Marin Pro Reef. I now have a tub of the standard Tropic Marin but haven't started it yet.

I have stacks of coralline so I'm not surprised I'm using up calcium. When I added some in-tank (under water) lighting recently it had coralline on it within a couple of weeks and a little while after it was pretty encrusted.

It will take me a long while to get through my new tub but I'll make a judgement call when I'm ready to buy a new one.

Cheers

 

[Colin_T]

I would buffer the KH. That will help stop the PH dropping and help reduce the amount of calcium being used to stabilise it.

 

[CageUK]

I would buffer the KH. That will help stop the PH dropping and help reduce the amount of calcium being used to stabilise it.

Problem is Colin the KH is quite high anyway. I intend to run a batch of tests today but last time I tested it was at about 10.5 so I'm a little reticent to buffer it much more.

 

[Colin_T]

If you have a KH of 10.5 you should not be having problems with the PH dropping. Perhaps the test kit is reading incorrectly.
Also is your magnesium level correct? 1140 seems a little high. Corals use calcium more than magnesium, which is generally used in small amounts and mainly when the calcium is gone.

 

[SkiFletch]

Oh, well if you're having trouble with waterchanges bringing down your levels, you can mix up a batch of water, test it, figure out how much supplimental addition you'll need using the Reef Chemistry Calculator and then every time you mix a batch of water, add that much of the suppliments to make it better