Lesson For Beginners

[karmagl]

oops I posted this in the wrong place the first time
I just thought that I would post this since everyone is new at sometime. We are a year or so into our freshwater tank but the first 6 months were hell. Our fish just kept dying. Our fish guy told us that the calcuim in our water was too high so we had to buy water from the store it got really expensive. We couldn't figure out what we were doing wrong and when I tell you fish experts your not going to believe how fish nieve we were. We went to our fish store and my daughter saw a beautiful sea shell she wanted, he says you know you can't put that in a fresh water tank right, when I asked why he said that it would raise our calcium and could kill our fish. Well of course when we went to petsmart in the beginning we found a cute shell that the people said would look great in our tank. Lesson learned DO NOT put shells in your freshwater tank.

 

[guppyluvr]

I didn't know that....You really can't put shells in a fresh water tank? Good to know.

 

[karmagl]

Thats what my fish guy told me and he is awsome with fish knowledge. I never would have thought.

 

[Tessla]

You can put shells in freshwater, but it will raise the pH and hardness which isn't the best idea for most fish. However, it also won't kill most fish either unless you're keeping something that absolutely requires soft acidic water (discus spring to mind). Certain African cichlids actually prefer the harder water, and some like the shell dwellers are often kept with shells.

Are you absolutely sure that it wasn't a cycling tank that killed off your fish in the first few months? It isn't very likely that a single shell placed in your tank killed off most of your fish.

 

[karmagl]

He said that it releases calcuim into the water and eventually will kill your fish just takes a while. When we started using bottled water we still had high levels of calcium and couldn't figure out why. We took out the shell and are now able to use tap water. He also said it was just sea shells.

 

[my fat fish]

i had a big ass shell in 1 of my tanks everythink was fine

 

[bymauldin]

I've got 3 large hermit crab shells in my aquarium right now. I haven't added fish yet because it just got finished cycling, but I was told that certain fish like shells as hiding spots. I imagine hermit crab shells are the same as sea shells? Am I wrong? Should I take them out? Hmmm....I knew they could possibly raise your Ph, but I've never heard the rest. Now, I'm concerned since I'm ready to add fish.

 

[Teelie]

Sounds like a load of bull to me. I keep freshwater shelldwellers with shells, 30+ of them and the fish need those. On top of that, I had Zebra Danios in there with them and they did fine. It's also unlikely a seashell would dissolve so much calcium so quickly into an aquarium to kill the fish like that. Not if you were doing proper water changes and dechlorinating the water.

What's more likely is your tank was not cycled and it was causing a die-off. I've seen dozens of aquariums with sea shells with all types of fish and they did fine. There are the exceptions like the aforementioned Discus but these are generally sold to more experienced or specialist fish keepers than someone new to the hobby.

 

[andywg]

Do not worry about it. If you used shells as a substrate then you will see your pH rise, but a few decorative shells will not cause major problems.

Also, do you have any idea what your calcium levels were? Calcium will dissolve into water over time, but I have never heard of it causing problems.

There seem to be a few scientific papers about the effects of calcium, but I can't open the entire article. Might be worth waiting for someone like bignose or nmonks to come along and let us know. From what I can see you need calcium levels of around 700ppm before there is likely to be any real effect on fish.

SW tanks (full of shells and calcium and even dosed with extra calcium) struggle to stay at much past 500ppm, so I find it hard to believe that the calcium from a few shells will cause a problem.

 

[CFC]

Its much more likely to be the unstable effect caused by the sea shells raising KH in the tank and softer water being added for water changes then diluting the water with the enhanced hardness and causing the KH and pH to drop which was killing the fish, unstable water chemistry is one thing that is a sure fire way of killing all your fish.

 

[Teelie]

Sounds like a plausible cause although I'm still not sure how seashell could raise the KH and pH enough to cause such a dramatic shift even with the softer water. Unless it was a very big one maybe? I've given up trying to manage water chemistry for the most part. It's more trouble than it's worth unless you have the time, patience and tools to get it just right.

 

[Tessla]

KH and pH fluctuations sounds plausible if extremely soft acidic water was being used, though I'd still suspect other factors (especially related to cycling).

If it was just calcium in the water, all of my fish would be dead as my tap water is absolutely wretched. GH is ridiculously high and that's mostly calcium and magnesium ions, plus according to water quality reports we've got quite a few more exotic metals dissolved in there as well. KH is high as well with so many dissolved minerals and gets my pH up to 8 right from the tap. That's higher than some aquarium test kits can go unless they're testing the higher ranges. Now while I can't keep discus, I've had no problem whatsoever with any of the tropical community fish I've kept.

A shell is going to add calcium carbonate to the water, which is a good thing if you've got extremely soft water with little buffering capacity as it will even out the pH and prevent big swings.

 

[Bignose]

I do have one thought on this. (I'll try to take a peek at the scientific literature later Andy). But, the main way fish regulate their internal chemistry is via exchange at the gills. The fish is usually pretty adept at exchanging ions, it can change its internal pH several units in an hour, but the conditions have to favorable. Which means a favorable gradient between the minerals in the fish's internal fluids, and the minerals in the water. If there is a lot of calcium, that is, high mineral content, it is not as easy to do the exchanges the fish needs to perform... maybe even has to expend energy to exchange against a gradient instead of using the gradient to its advantage. Working harder to perform your basic functions would be akin to having slight asthma your entire life. You can live a reasonably healthy life, but your body will be more stressed, leading to a slightly weaker immune system. I know someone who has asthma, and she seems to catch every cold that goes around every winter. I wonder if the fish might be like that, being slightly stressed from having to work against that more unfavorable exchange, then when any problem does arise, they are more susceptible.

If andy's preliminary search is right, it would take some exceptionally hard water to cause problems. 700 ppm is about 39 (German) degrees of hardness. My water is 23 GH and 13 KH, and the fish have been fine in that for years.

karmagl, can you post your water's GH and KH?

 

[karmagl]

I honestly don't remember it was like 6 months ago. I do know that our calcium levels are a little high anyways from our tap. And I do remember our fish guy saying that the calcium levels weren't sky rocketing but it was high enough that over time it would stress the fish out and ware on their skin.