Excessive Cleaner Shrimp molting

[Schnizzle]

I picked up a nearly full grown cleaner shrimp, simply because I like them. Around the same time I sent off an ICP test. It came back high in a few heavy metals (chrome and vanadium, which I found and removed the source) and suggested weekly 20% water changes over 3 weeks. I did the first one and the shrimp molted. I attributed it to chance timing. Did my second one last night and it molted again afterwards. I match the salinity to 1.026, the temp to 78f, let it sit overnight with a pump running on the bottom pushing water up to oxygenate and settle. I need to do one more water change this Sunday. I doubt it is my fish harassing it because they have taken no interest in it at all and I spend way too much time watching this tank. haha

Am I going to kill this guy if I make it molt again this weekend? Is a water change enough to cause them to stress-molt?

4 firefish, 1 red banded goby, 1 royal gramma and 1 blotched foxface
90 gallon DT, 30 gallon sump, ~103 calculated system volume
7.9 pH
8.6 dKH
.045 PO3 (had a macro vs GHA issue that has been solved, I hope)
3 NO3
490 Cal
1380 Mag
0 ammonia and nitrite

 

[RobZilla04]

If I'm not mistaken high iodine could be the cause here. Are you dosing any?

 

[Schnizzle]

I am not dosing anything yet. Iodine is about twice the ideal value, 136.2 μg/l measured vs 62.63 μg/l "ideal"

I'm going to dose .5ml of Manganese per the ICP instructions after this next water change.

 

[RobZilla04]

I am not dosing anything yet. Iodine is about twice the ideal value, 136.2 μg/l measured vs 62.63 μg/l "ideal"

I'm going to dose .5ml of Manganese per the ICP instructions after this next water change.

Try searching to confirm, but I highly suspect the increased Iodine is causing it. Which salt are you using? Would be interesting to know how it got that high without dosing....

 

[Schnizzle]

Reef Crystals. I was planning on adding corals around this point but I’m suddenly moving in the next few months so I’m holding off on adding other life.
I searched iodine and shrimp molting and yeah, it seems you’re overwhelmingly correct. Haha Thanks!
I’ll see if I can find a test kit and test my freshly mixed water this weekend.

 

[RobZilla04]

I can remember Randy avoids Reef Crystals due to organics. You can try searching for some of that info as well. I'm not sure what those are or to what degree.

If Iodine being increased is the only reason you are holding off on coral, you may not need to do so. With a fully stocked tank, I need to add Iodine. The coral growth may help remove the excess in your instance. Especially LPS and softies.

 

[Schnizzle]

I'll check that out. I'm holding off on coral because I physically have to move to a new house about 30 miles away. 1.5 months into the tank being setup and running I found this out...

 

[RobZilla04]

I'll check that out. I'm holding off on coral because I physically have to move to a new house about 30 miles away. 1.5 months into the tank being setup and running I found this out...

In that case, definitely hold off.