Hyposalinity questions

[crumbletop]

I am 10 days into hyposalinity treatment (1.009 SG as measured by a calibrated refractometer). There are two fish; a pigmy angel and a firefish. Neither fish had any visibile signs of ich at the start of treatment -- they are "carriers" of ich from a tank where there was an ich outbreak that "resolved." I am treating them while letting my display sit fallow for 6 weeks. They have done well so far, but starting a couple of days ago I have noticed ich appearing (salt-grain) lesions on the angel. The angel still appears to be doing fine, but I am nearing the end of the recommended 2-week treatment, and after reading some correspondence that Steven Pro had with a fish disease expert, I think I may have lowered my salinity too slowly? I initially lowered the salinity from 1.027 down to 1.009 over two days. Steven Pro recommends dropping the fish right into hypo, and it appears so does the fish disease expert with whom he was corresponding. Apparently, the osmotic shock (rapid lowering) is what does the trick -- not necessarily the conitinued low salinity. I still have about 4 weeks left for my display to remain fallow and as I see it I have a few options:

1) Finish out the two week course of hypo and gradually raise the salinity. No more ich treatment required. The salt-grain lesions on the angel are nothing to be worried about.

2) Continue the hypo for another two weeks after the last of the lesions has disappeared.

3) Gradually raise the salinity back up to normal, and then do another hypo treatment but this time use Steven Pro's recommendation of dropping the fishes right into 1.009.

4) Gradually raise the salinity back up to normal and treat with copper (I'd like to avoid copper).

5) ???

Thanks in advance for any help or guidance!

Jack

 

[cristhiam]

I would just continue with the hypo treatment and count 4 to 6 weeks after you see the last ich fall out. 6 is the recomended. I would do water changes too, vacumming the bottom of the tank. Check your PH and amonia while treating the fish. PH sometimes gets too low at low salinity. Check out this link.
http://www.petsforum.com/personal/trevor-jones/hyposalinity.html

 

[gotoneon]

I agree with cristhiam, I have had fish in hyo for 8 weeks, just to make sure. It is better to be safe, you will create a lot less stress for you fish leaving them in hypo then putting them back in the tank early and catching them two months later to re-treat everything.

 

[crumbletop]

Thanks. I appreciate the feedback. I've been keeping the pH steady at 8.2, and have been doing water changes of about 25-35% every 1-2 days depending on the ammonia level.

Also, the link above is the main link I had been following wrt the hypo treatment. The fish don't appear too stressed, although they don't seem as comfortable with the pvc parts as they did the caves and caverns in the live rock. It makes sense to stay the course, although it seems odd that ich would show up at this point. I'm actually 12 days into treatment. I'm not familiar enough with the life cycle of the parasite to know if these lesions could only be coming from organisms in the QT, or whether or not they are more likely outward manifestations from ones that attached while still in the display.

Thanks again for the help.

Jack