Arrow Crab Dead, and Brittle Star shrinking

[mdelp]

My arrow crab didn't feed yesterday which should have been a huge red flag for me, and today he's dead. And now it looks like my brittle star is dying, it's shrunk very small.

I have a tank for quarantining, but that's it, no air stone or bubbler or filter for it. It's late here but I could run to a box store and get that stuff, if people think it would save my brittle star.

I'm not sure what's happening, but I recently started replacing evaporated water with tap water with a double dose of prime in it (There seems to be a lot of ammonia .. I assume Chloramine ... in my tap). I was using strictly RO water before. Also my salinity levels seem to be lower than usual 1.021 down from 1.023.

Temperature: 82, thermostat set to 78
Ammonia: .25-.5
Nitrite: 0
Nitrate: 0

So could be chlorine, could be the salinity thing. I'm considering adding salt to the aquarium and/or quarantining my brittle star. Any thoughts on what's doing this and how to fix??... do I need to quarantine my brittle star right away... or can it wait till tomorrow??

 

[Calappidae]

Could be copper or chloramine, you should test for those.

Tap water with prime dosage isn't reliable. Regardless of what water conditioners say, there are still a few pathogens that may bypass the product and still end up in the aquarium. Your best bet would probably be to buy some water from the LFS, or distilled bottled water from the store until you get a proper RO/DI system.

As far as what to do with the star itself, I'm not sure. It's hard to narrow down the situation. It's not starvation I pressume, there could potentially be a starfish disease, although the arrow crab makes that seem unlikely. Which leads me to think this is an overall system problem.

Do you dose with anything like buffers bar prime?

 

[mdelp]

ok, after doing some research it seems like salinity is probably the problem. I'm going to use the handy calculator at http://www.saltyzoo.com/SaltyCalcs/SalinityAdjust.php and up the salinity level.

 

[mdelp]

Could be copper or chloramine, you should test for those.

Tap water with prime dosage isn't reliable. Regardless of what water conditioners say, there are still a few pathogens that may bypass the product and still end up in the aquarium. Your best bet would probably be to buy some water from the LFS, or distilled bottled water from the store until you get a proper RO/DI system.

As far as what to do with the star itself, I'm not sure. It's hard to narrow down the situation. It's not starvation I pressume, there could potentially be a starfish disease, although the arrow crab makes that seem unlikely. Which leads me to think this is an overall system problem.

Do you dose with anything like buffers bar prime?

No I don't dose with anything. I was just adding prime to the tap water, to get the ammonia levels down.

I've been using RO from my LFS since I started the tank. I just tried doing this tap water thing a week ago, but there's so much ammonia in the water (or chloramine) that I had decided to go back to RO. Alas too late for my crab.

Thanks for replying. I'm going to raise the salinity, do I need to do this slowly over several days? or can I do it with a few water changes in however much time that takes?

PS, my shrimp seem to be doing okay... cleaner, and peppermint

 

[Calappidae]

Well, you don't want it to be a sudden shock, but at the same time you don't want to leave them in poor water quality for extended periods of time (do you have a hydrometer/refratometer? Do you know your specific gravity?) so I would do it slowly like a point or two an hour, but not all in one water change.

Might want to hear a second opinion on that as I'm not too sure how people go about raising low salinity. I guess it boils down to how dangerously low or high it is.