[smidoid]

Well, I lost my cleaner shrimp this time. When I heard the kids screaming this morning I assumed she'd finally molted (I noticed the pre-molting behavior - picking at it itself over the last few days.)

However, the "corpse" appears to be full, so unless she's shrunk and hidden somewhere, it's game over.

I don't think this is general a tank problem, the only change yesterday was a the fortnightly good stir to clean away detritus at several litres of fresh top-off water (we're having a heatwave here). I assume this is coincidence. The other inverts (including a coral band/boxer shrimp) seem unaffected.

My guess (unless this was purely natural) is the one thing I am unable to adequately test for: iodine.

OK:

• so, anyone have a suggestion?
• could it have been the slight salinity decrease?
• if it's iodine deficiency, what do you recommend?

[leebca]

A cleaner shrimp is relatively hearty. Not easy to put one 'down.'

I'm not sure what:

slight salinity decrease

means. It could be a factor, but without more details, I have to set that one aside.

I'd vote for the most likely scenario that it had a difficult molt. This would likely mean the need for more iodine in the water.

Although my aquariums are 'technically' FOWLR, I have several cleaner shrimp. I add trace elements to the water for my fish according to my post:
Feeding Marine Fish and Fish Nutrition
and I also add an iodine supplement monthly. So my tanks get a bit extra iodine (some from the trace element additive and some from the iodine additive).

I have never measured iodine. I just follow the above additions and perform weekly water changes (10.22% )

[smidoid]

Salinty drop meant that I dropped the salt conc. slightly by adding more water. Maybe 4% extra fresh water as a top off; but only as a top off. It was used to the salt conc. since I've had it.

I'll take a look at that post later. Problems at the ranch.

[bongobrian]

What are your specific gravity levels before and after the top-off? most inverts are best kept at a higher specific gravity such as 1.023-1.025. Inverts are less able to accomodate changes in their environment than fish. It's the reason why people with fish only tanks will often keep their sg levels lower around 1.020 because parasites, which are also invertebrates, will typically not survive in a low salinity like this.

[smidoid]

From memory, it's reading 022, but the swing hydrometer is anything but accurate (tends to read low). I'll have to wait until the LFS opens to get a more accurate reading. It's the total fill was less than a gallon of fresh into a 50 gallon (running) system.

I'll get back if there's any surprise.

[sihaya]

If you ask me, swing arm hydrometers are useless. I don't think any reef-keeper should be without a refractometer. In my opinion, if you can't afford one, then you can't afford to keep a reef tank. I hate to say that... but the truth is, it's an expensive hobby and these animals are precious and the reefs are dying. It's not anything anyone should do half-arsed.

[captain Jim]

Sorry to hear about your loss! First nemo now this? When will the madness end?
Are there any other changes in your tank or refugium that you have noticed?

[sihaya]

Oh... and sorry, regarding the topic. I can't keep cleaner shrimp alive. I have no idea why. And it's so sad because my husband loves them and I wish I could keep one for him... but they just always die in my tank. It's just odd. It's the only thing I haven't been able to keep (well, aside from that one doomed carnation coral I never should have bought).

So I don't know... you may not be able to figure out why it died.