Can Ich-X kill bladder/pond snails?

[Jess]

Back story:

• June: got 12 crossband chocolate gouramis (45-gallon planted tank) [I've posted about these guys recently]
• October 10: got 6 healthy-looking otocinclus from my LFS (let algae grow for 5 months before getting them) 
  • also added 6 habrosus corys from one of my other tanks; I've had them since July
• October 17: cold snap, woke up to all tanks down from 78 degrees to 66 degrees. Plugged in all the heaters, most of the fish were ok but one chocolate gourami was struggling and another one was missing (usually they are begging for food, so missing = sick or dead).  The sick one didn't have any visible spots or sores or anything, just couldn't swim. He died within a few days. 😞  All other fish in other tanks still ok.
• October 24: noticed a couple of tiny spots on fins like ich on the gouramis (only) so bought Ich-X from the Co-op.
• October 31: started Ich-X treatment (I was delayed because I needed other stuff - quarantine tank, extra heaters, had issues with the new heater not heating the water enough, ended up dosing the full tank with Ich-X, hoping for the best). By this time the ich had spread a little (on some fish more than others); I really wish I hadn't been so afraid and had started dosing the main tank when the Ich-X arrived.

Medication course so far:

• October 31: Ich-X, 4 tsp. I routinely see 9 fish out of 11, so 2 are either sick or dead but I can't find them.
• November 1: 30% water change, Ich-X, 5 tsp (not really sure if the amount is based on total water volume or tank size...but I realized that I also am running an Eheim 2217 that holds like 1.5 gal water so I figured 5 tsp is probably ok). No visible difference in fish symptoms, but one fish died and I still see 9.
• November 2 (today): harvested a massive amount of dead pond snails!!!  Most just lying on the substrate, some half out of their shells...definitely dead by the smell when I removed them (sorry to be graphic...but yes they're really dead).

Question: before I do a 30% water change and dose again with 5 tsp Ich-X, is there any thing I should be aware of or check or test?  Because Ich-X is supposed to be safe for invertebrates so this massive snail die-off is really concerning me.  I'm using Seachem Prime to dechlorinate...a search on this forum revealed a post by Cory saying he's never had a issue combining Prime and Ich-X in the same tank.

Parameters (all except ammonia using Cory's test strips):

• Ammonia: 0-0.25ppm (I am pretty sure it's 0...this is using API test kit); Nitrite: 0 ppm
• Nitrate: 25 ppm (this is normally 0-10ppm, so it may reflect dead snails I don't see....good, means my bacteria are still healthy)
• pH: 6.4
• KH: 0-20 ppm, GH: 75 ppm
• Temp: 78 degrees

 

 

 

[Zenzo]

Ich-X shouldn't have any impact on the snails. In fact, in some cases, I wish it did (to help rid certain tanks of too many snails).

I have also never had an issue with Prime and Ich-X together. 

 

[Jess]

Hmm...so what do you think could have caused the sudden die-off?

My fear is that something else is going on that I cannot "see."  I just can't guess what it might be.  The only thing I can observe is that the gouramis have ich - like I said, some worse than others - and the otos and the corys look fine (no visible ich). 

The gouramis are highly sensitive to temperature and possibly also GH.  This tank was previously around 150ppm hardness and over the last week or two I have dropped it to 75 ppm.  People talk a lot about how hard water fish often can't tolerate soft water, but I was unaware that the opposite is also true.  So all of these may have been struggling internally with the added mineral content, and then the cold shock weakened them further.  The otos may have brought the ich or it may have been present already, just not causing any problems until the cold shock weakened the gouramis.

That said, I've also decreased the hardness in one of my other tanks down from 150+ to 75 ppm for the same reason, and no snail die-off there.  It houses soft water fish and while they don't appear to be negatively affected right now, I don't want to shorten their life span.  My tap water is naturally soft; I was remineralizing using Seachem Equilibrium to help my plants, which were suffering from the low mineral content.  I'd rather keep the fish comfortable and replace the plants...I didn't know hardness could shorten their lives until I started reading into it and found that some aquatic vets think the minerals deposit on their organs and cause early demise.

I'm really perplexed.  I've removed all the living snails I can find and put them in my quarantine tank for observation.