Petshrimp.com Discussion Forum

Is it possible that shrimp consume or find in the water column too much calcium and their shells harden too much that they will have difficulties molting?

Thanks,
Pedro

In most (probably all) water supplies there is always more calcium in the water than the tiny amounts the shrimp needs. It would make no evolutianary sense if a shrimp "overdosed" on calcium. I am sure the shrimp has some regulatory control over it.

However, for some shrimp, such as bee shrimp/CRS, too much calcium (as in adding tons of calcium to the water on purpose) is probably not optimal, as calcium increases conductivity/TDS and these shrimp seem to prefer low conductivity (refered by many others as "hardness").

It has been observed in on eof my CRS tanks. Do you think using completely distilled water is bad for them?

-Pedro

If you really mean "distilled," as in pure H2O, then I would not recommend it. Although the wild cousins of our CRS live in very low conductivity water, there is always something in the water still. Just RO water should be fine, but not DI (deionized) water. I would get a conductivity meter and measure your water. Usually, RO units still leave enough ions in the water so that conductivity is somewhere around 10-50 microsiemens/cm, which is ok. My tap water has a conductivity of about 80, so it's almost like RO water. If your conductivity is too low, you can still mix some of your tap water in with your RO water. Just mix in a little bit at a time and measure conductivity until you get the right number. Also, do a search on "conductivity" to see some of the threads where similar issues have been discussed in connection with bee/bumblebee/CRS/serrata group shrimp.

Well, Distilled water like the one you buy at the supermarket. Not sure if it is the same as Deonized. My RO water has high ph, so I would have to lower the ph. Also my RO water has 0 conductivity. I might need to go the muriatric acid way to keep things under control.

-Pedro

Distilled water from the supermarket is just pure water...0 conductivity. If your "RO" water has 0 conductivity then you *must* have a DI stage as the last stage of your RO unit. DI stages are very common to RO units. For your purposes you might want to disconnect the DI stage or just mix in a small amount of tap water to get some minerals into your processed water.

It is probably not only for conductivity. Calcium is an important second messenger in signaling pathways in the metabolism of any living animal. Calcium ions usually only contribute only a small part to conductivity of most waters.

Distilled water from my market (pouland springs)has higher conductivity than my R/O water. All distilled water isnot created equal. If there is carry-over in the steam a loot of mineral content can end up there.

Co2 from the air will dissolve in destilled water, if it stands around for some time. As HCO3- and H+ ions it will increase conductivity

zwergkrebszuechter wrote:It is probably not only for conductivity. Calcium is an important second messenger in signaling pathways in the metabolism of any living animal. Calcium ions usually only contribute only a small part to conductivity of most waters.

With natural water supplies, if you have any conductivity at all, there is usually some calcium in there. Calcium is a major ion in all natural waters after all. I don't know why you think that calcium only contributes a small amount to conductivity of natural waters, but that's not really true. It's a relatively large amount in many rivers. I just read a paper about the chemical composition of the major rivers in India and calcium is the second most common ion in those rivers, right after bicarbonate (HCO3-) and before sulfate.

Plus, there is always calcium in the food that you feed your shrimp, even if it's not specifically mentioned as an ingredient. Nobody said that calcium is not important.

I don't quite understand what your general point is, though. What are you contradicting when you say: "It's probably not only for conductivity."? What's not for conductivity?

The problems that calcium can cause to soft water fish and invertebrates...
There was an article in the Datz some months ago. A scientist said, that the problems calcium cause are not only for osmotic stress, but can cause chaos in the signal pathways of non-adapted critters. So the metabolism goes all wrong.
Adapted critters can control the number of their calcium channels in the cell membrane and thus control the calcium concentration, while non-adapted cant. There was something in there that it is more easy to adapt fish from hard to soft water (if they can stand soft water of course) than vice versa. Because the number of calcium channels can be upregulated very quickly but is slow to be downregulated. Some critters that live in soft water for many generations have lost the ability to downregulate because they never needed to as there is few calcium available.

Ok you are right on that one, calcium is one of the most important ions for conductivity in fresh waters. I remembered that wrong, just looked it up.