Ich or flukes in hypo? Confused

[kaiboshi]

I have had my 355 gallon system in hypo for >8 weeks as of today, 8 weeks since the last spot disappeared. I skipped QT on some cuc inverts in late may/early june and ended up with ich. Interestingly, someone else posted a thread detailing very similar events with inverts from the same vendor purchased at the same time.

Throughout the process my fish have occassionally flashed, scratched and shimmied. I know a certain ammount of scratching is normal but this was above and beyond the norm. I also know that at least one of my fish had internal parasites and at least one had to have external parasites because I didn't treat a few with praziquantel prophylactically.

I had fish in QT undergoing TTM when the ich outbreak occured and I was using DT water for the TTM (under the assumption that my fish were clean) so I restarted/completed TTM then added them to my DT in order to do a mass praziquantel treatment. I was an idiot and didn't realize that treating 355 gallons is very different than 10, 20 or 40 so the bottle of prazipro that I bought only afforded one round of treatment. I did one round of treatment anyway and the flashing stopped almost immediately (about a day). The fish that had the internal parasites was cured and made a miraculous recovery. After 1.5-2 weeks the flashing resumed and is slowly spreading.

My concern is over the timing. The flashing/twitching/etc isn't constant. It seems to be an issue for a few days then the individual fish is symptom free for a few days. The timing seems more like ich to me than flukes as IME the irritation from flukes is more constant. It could be the recovering fluke population after the prazi treatment but I don't know and I'm very concerned that it may be ich.

I've never done hypo before because I don't trust it like I do the TTM or copper however my hands were tied with my entire system having an outbreak. I've maintained the salinity at 20.4 ms (which should be ~1.0085 sg or ~12.3 ppt) and 78 F. I've verified the salinity with two calibrated conductivity meters, a couple of refractometers and a crap hydrometer. They all agree that the salinity is somewhere between 1.008 and 1.009 sg.

Does anyone have any ideas? Am I likely looking at persistent flukes or persistent ich?

If flukes, what about treatment? I bought a big bottle of prazipro so that I can do multiple rounds of treatment but I'm not sure the most effective way to dose. I emailed hikari and they suggested I do two or three 7 day long baths. I've also heard that prazi only remains in the water for 72 hours so I'm not sure which is the best option. Any help would be greatly appreciated.

 

[GroktheCube]

Are you trying to treat in the DT instead of an HT? Your life would probably be much easier with the fish out of the tank as opposed to keeping the tank hypo for 72 days.

Some strains of crypto are resistant to hypo, and hypo usually doesn't help.

Usually for flukes, 3 or 4 rounds of prazi spaced 5 days apart (with a large WC prior to each) does the trick. It kills adult flukes very effectively for the most part, but not the eggs, hence the need for multiple treatments.

 

[HumbleFish]

When using Prazi to eradicate flukes you dose once, and then 5-7 days later do a 25% WC and dose again. The second dose knocks out any "newborn" flukes before they can lay eggs of their own (Prazi only kills worms, but not their eggs). I've never used Prazi in conjunction with hypo, so I cannot say whether or not it is safe to do so.

Hypo has been known to fail when treating for ich, especially in a DT. If you could catch one of the fish shortly after you see the twitching, you could perform a FW dip to confirm flukes.

 

[Newsmyrna80]

As Humblefish suggested...FW dip to confirm flukes then treat accordingly. Btw flashing is not normal behavior in a healthy fish.

 

[kaiboshi]

I'd like to treat in hospital tanks but my system, which is made up of 3 tanks, has fish in each tank that aren't compatible with fish in the others. I simply don't have the extra space or equipment to treat them in hospital tanks.

Keeping the tank at it's current salinity isn't particularly difficult however I worry about damaging the fishes kidneys if I I keep up the hypo. The tank reached it's current salinity on 6/15 and the last spots were visible on 6/22. I waited 2 days after the last spots were visible to start the counter, that's how I ended up with 8/19 as an end date (8 weeks). As of today the tank has been at ~1.0085 for 65 days. I'm not sure if I should leave it another week or not.

From what I've read the resistant strains are resistant to salinities between 1.009 and 1.010 however below 1.009 should be effective. Can anyone weigh in on that?