Fiddler crab and Fresh water clam questions

dodgefate

I Have a 55 Gallon tank and am kind of new to the whole fish keeping thing. I keep my PH at 7.9 and temp at 74-76. I have 8 freshwater clams (About the size of top necks) and two fiddler crabs (male and female) and a bunch of fish. What I am looking to find out is can I add anything like calcium to the water to help healthy growth of the clams and crabs without affecting the PH and health of the other fish; Or should I leave well enough alone?

1077

Clam's are filter feeder's and derive their food from filtering it from the water.Are difficult to care for for this reason ,they would like mature tank near pea green algae colored water to extract that which they eat.Most die fairly quickly, and it can be tough to tell if they are dead/ buried in the substrate, but dead ones could foul the water depending on size,and number's.
Many of the crab species, require slightly brackish water to full marine condition's, and more than a few need to be able to leave the water on occasion.
Might perform some more research on these invert's to see what they require for long term health.

Reefing Madness

Yes, you need to add a Calcium suppliment to the tank for the Clams. They need this in order to grow. Without it, they will not survive. FW Clams are not the easiest to keep, as you must target feed them. And your water cannot be that clean, as they need "dirty water" to survive also. Meaning they need Nitrates to filter and grow also.
In any case, buying clams for your aquarium is a bad idea. Even if we were to assume that these “shark tooth clams” (the shell is shaped very much like a shark’s tooth) are truly freshwater clams, they don’t have much chance of survival in an aquarium. Clams are filter-feeders that pump water in and out, and filter out the particulates in it for food. In the wild, there are a lot of microorganisms and detritus in the water, and clams live on it; but in the aquarium, they starve. The water is just too clean for them.
There are other issues with keeping clams. One is that they dig. Some will dig out of sight within moments of being placed into your aquarium — never to be seen again. How much fun is that? A forum message regarding these “shark tooth clams” said that they were 5 to 6 inches in length. If you had plants, a clam that large probably won’t dig out of sight, but it will uproot your plants as it crawls around.
Another possible issue is reproduction.

There is one more issue with keeping clams or mussels in your aquarium. They need plenty of calcium to build their shells. Your water may not be hard enough for them to do so. The shell will soon become pitted and discolored as it dissolves away.

I highly recommend that you avoid keeping clams in your aquarium; they are destined to starve. Some people have success with clams in ponds. The water there is usually substantially dirtier and full of microorganisms. But there should be substrate so that the clams can dig safely away from any fish that might hound them.

squishylittlefishies

Do you have land access for the crabs? this is verry important, they need to breathe. If you have no way to make a beach or land area for them, you can make an underwater dry land zone. Just lay a galss jar in th bottom of the tank, tilted so the mouth is angled down. keep it in this position as you place t underwater, so the air stays trapped in the jar. fill the bottom with gravel and rock. The crabs will just siddle in ad chill in there to breathe!

squishylittlefishies

Google "underwater dry zone fiddler crab". The first link is good. Even if you do have land access, I still think this is a fabulous idea. back to the original quastion though, no, I would not reccommend supplementing calcium or anything.