molting problems???

[pleco_breeder]

Hello all,

I've been away for a couple days for the birth of my daughter, but have a rather pressing question about molting in my cherry tank. Since starting the tank, I've gone through a series of deaths and finally think I've got them figured out. Because of the small tank size 1 1/2 gallons, I have to do water changes a bit more often. I've been doing 30% every 3-4 days and the deaths have stopped since I started. However, half the population is molting with every water change.

I'm unsure if this mass molting is because of good water quality, or if I'm stressing them to no end trying to maintain water quality. Any ideas of whether this is something to worry about? As I said, the deaths have stopped, but I really don't think it's normal for shrimp to molt this often.

Thanks,

Larry Vires

[Suzie Q]

I can't answer your question, but Congrats on the birth of your daughter!!!!
Lori

[apistomaster]

Hi Larry,
It does seem likely that the difficulties of trying to control stability in such a small volume could very well be the problem.

I have never tried to keep RCS in less than a ten gallon aquarium. It always seems like a nice size for maintaining quite a few shrimp and still is easy to keep up. Small enough that even a few pairs or trios wll soon undergo a population expansion to several hundreds counting every size.

[pleco_breeder]

They were originally in a 10 gallon, but went to the smaller tank after the heavy initial losses. I spent a lot of time thinking about this today, and am curious if smaller daily partials may be easier on the shrimp.

Larry Vires

[badflash]

It sounds like maybe your water conditioner isn't as good as it should be. I swear by Amquel+ and swear at Seachem Prime. IMHO Amquel does a much better job at chloramines. The water company may be stupid enough that they can't tell the difference between chlorine and chloramine. Mine is. Standard water conditioners end up making ammonia when theyreact with chloramine.

Mass molting is a sign of stress, and timed with water changes the cause is pretty easy to determine. You might change water conditioners, and try letting the conditioner work at least 10 minutes before adding the water. I use a drip make-up on my sensitive species to reduce the shock.

BTW- Congrats on the new baby! We also have a grandchild in the house just born a few weeks ago, so I'm right with you!

[apistomaster]

Hi Larry,

You are pretty handy as a fishroom engineer. What about supplanting the small volume shrimp container with a 5 gallon "refugium" where water drawn through a sponge prefilter from the shrimp tank goes into the larger "refugium" and returned?

I'm just suggesting some arrangement like this to produce a more stable environment yet allow for concentrating the few shrimp where they would have frequent romantic interludes.

Larry W.

[pleco_breeder]

Hello,

I've changed my routine a bit since realizing that there may be a problem. I'm now using water from one of my BN tanks as replacement water. That tank is currently getting daily 10% water changes, so the replacement water is reasonably fresh, but aged enough to prevent WC problems. It may seem like a lot of work to some, but it's really only another minute in a 2 hour daily routine. Up to this point, only 3 days, it seems to have remedied the problem.

Larry Vires

[Cactus Bastard]

I know bumping old threads is generally frowned upon, but I would really like to hear people's thoughts on this idea.

Hi Larry,

You are pretty handy as a fishroom engineer. What about supplanting the small volume shrimp container with a 5 gallon "refugium" where water drawn through a sponge prefilter from the shrimp tank goes into the larger "refugium" and returned?

I'm just suggesting some arrangement like this to produce a more stable environment yet allow for concentrating the few shrimp where they would have frequent romantic interludes.

Larry W.

I built a stand recently that is just waiting on a few finishing details before being set up with tanks, and one of my design criteria was to include plenty of space for sump(s). I've been considering setting up a shrimp tank on it, but I was worried about diluting their food supply.

[badflash]

I think the sump system is great as long as you devise a method to keep the shrimp from getting into it. I use an undergrave filter to pre-filter the sump and connect the overflow via a 1" PVC pipe. My tanks are drilled with a 1" bulkhead connection for that.

Most people overfeed their shrimp, so this really isn't much of an issue with food.

[Pugio]

This is an interesting thread I found looking for some answers...esp. about the "mass molts" of shrimp under stress. I've noticed the same with water changes (but not sure if that's b/c I am more attentive to the tank afterwards).

I read a recent article about fiddler crabs living (reasonably well) in polluted waters near New Jersey (aka, the Garden State) - turns out these fiddler crabs dispense of toxic heavy metals in their exuvia via each molt.

This review should work: http://www.bioedonline.org/news/news.cfm?art=3469

That got me thinking - so when I looked further online there is other research on how shrimp (e.g., the ol' laboratory workhorse, Palaemonetes) export heavy metals (esp. copper, zinc & lead) - and possibly other industrial toxins - through each molt.

So now I'm not 100% sure if colonies of captive-bred shrimp should be continually eating the exuvia of other fellow shrimp - and therefore bioconcentrating possible toxins or heavy metals. I know tap water in USofA is very clean but maybe at some point there is a price for this free meal (the calcium of which may be mostly resorbed by the shrimp prior to each molt)...I dunno.