Bert H

Does anyone know the availability or utilization of Ca in water where there is high CaCO3 (calcium carbonate) from limestone rich waters? I seem to recall reading sometime ago where there was some mention of the fact that this form of Ca was difficult for plants to utilize. Anyone have any good info on this?

Having hard water (kh 9-10) from a limestone aquifer, it surprises me that my snails can develop holes in their shell. Guppies and SAE's won't cause this. I have noticed recently that some of my nerites have cracks and holes in their shells. Frankly, that's the last thing I would have expected. It makes me wonder also how this might affect plant utilization.

Bert H

Anybody...???

Zapins

Interesting. I haven't heard of there being a difference in utilization between chemicals.

CaCO3 should dissociate to Ca (2+) and CO3 (-2) ions just like any other calcium salt so I don't see why there would be a difference in absorption - it should be the same ion. If I remember correctly, all the chemicals we use for dosing our tanks with Ca all dissociate to the Ca +2 ion.

Iron on the other hand can dissociate to have a different charge on the ion depending on what it was bonded with. So there will be differences in absorption with iron.

Anyone else have an idea?

wet

the real reason may be past my understanding, but could itbe that this memory was from folks advising against the very slow to disolve caco3 in favor of cacl and caso4?

Bert H

You're right, a Ca++ ion is a Ca++ ion, seems that the source shouldn't matter. Perhaps I should look at other possible causes for nerite shell cracks and holes. Any ideas on that one?

Zapins

Excess CO2 might be the cause. I noticed that even in very hard water (GH of 19) my snails developed etched and damaged shells.

Maybe feeding them a calcium supplement like egg shells or calcium pills from the pharmacy might slow down the damage. Have a look at this thread for some ideas on what to give them.

http://www.aquaticplantcentral.com/f...um-snails.html

edwardn

Hej Bert, I have a bag of pelletized dolomitic lime. If you would like some, I will send it to you by Randy-post Just say it...

Regards

Edward

Bert H

Thanks for the offer Edward, but I have plenty of Ca in my waters, too much actually. I assume Randy-post got you the petites ok.

ShaneSmith

Bert i highly doubt that the damage to your snails is from Ca deficiency, there must be another factor. If your sure non of your fish are feeding on the snails look into snail nutrient requirements. Maybe something else is missing in their diet that they need to untilize calcium...