Need advice


Reefing newb
Reaction score
Hello, I have a ten gallon nano that has been stable and beautiful for three years. I do a weekly one gallon water change on this tank. I did the water change on tuesday, in a few hours both shrimp and crabs looked bad. They are still alive but barely moving and not eating. All the water parameters, salinity alkalinity, temp and ph check out fine. I even did an amonia and nitrite test to catch maybe a spike but those were zero. All corals and clownfish and snails very happy, business as usual, crabs and shrimps very bad. I figure I must have accidentally poisoned them with something, but I cannot think what, I did the water change exactly as I have been doing it for three years. My question, I did a water change a little while ago and am planning on doing one tomorrow. Is that my best bet, just doing a water change every day til I dilute what ever is in the tank? Am I missing something? Any help would be appreciated. Thanks, Teresa
Do you use tap water?

If so i would check your nitrates, maybe there was a spike in nitrate from you water supply company.

Nitrates don't bother fish etc at lower levels, but will seriously cause problems for shrimp, crabs, snails etc......

Other than that I'm not sure what to tell you...

Did the temp change drastically, did you open a new bucket of salt, did you use a bucket to mix the water up in that someone might have used to mop the floors.... Do you have two salinity testers? Those can go bad and your salinity might be the issue....

It is really hard to say for sure, but those are all some things you might want to check.

Hope this helps
Checked nitrates

Hi guys I checked nitrates as suggested less than 10 ppm in tank and tap so thats not it. It is possible that something could have gotten into the bucket that I mix the salt in but nobody mopped the floor with that bucket or anything like that. I did another water change today and things are still the same, crabs and shrimps alive but not moving much. What gets me is the snails and even tiny fan worms are not affected, just shrimp and crabs. Thanks for your replies, Teresa
if in doubt about something poisoning your water such as copper, or chlorine or some other chemical or contaminate stick a poly filter in the filter, it will pull out just about anything quickly and safely, also if it turns certain colors you can tell what the contaminate was. they are usually about $8 to $10 at local stores or $5 in catalogs. good luck

Hello, Ironman, Thanks for the advice, I just ordered the Magnavore Pura pad online. Unfortunately, my shrimp died and the crabs still look bad so I will just use this filter for a couple of weeks and then maybe add a hermit crab from my other system as a test subject. This magnavore stuff is supposed to remove most any contaminants and heavy metals including detergents and stuff so maybe this will fix my problem. I did not know such products existed so thanks again, I appreciate it. Teresa
as you now know things can happen very quick and its best to keep those pads at all times cause hours count. good luck and let us know what happens