Hyposalinity Treatment, Part 1

Well, I've finally tried to do something about it.

Fins, our sailfin tang, didn't show any signs of ich (the dreaded fish parasite Ichthyophthirius multifilis) when we bought him, and the quarantine tank was filled with my mom's porcupine puffer (Diodon holacanthus) whom she wanted out of her tank and sold, so I opted not to quarantine him and threw him into the display tank immediately. I was well aware that tangs often hide ich inside their gills, but I was hoping for the best.

In any case, the first sign manifested on his tailfin about three days later. With the puffer still taking up my QT and not wanting to have to deal with a sick fish, I told myself that it was the nutritionally related fish virus Lymphocystis, and changed up his diet. With time, the sign on the tail was gone. But then it made a strong reappearance and I was convinced that we had ich.

Finally, yesterday and not a moment too soon, someone came and picked up the puffer. I quickly prepped the QT for hyposalinity. Hyposalinity is a method of curing Ich by lowering the specific gravity (the salt content) of the seawater to level that the fish can live but the parasite cannot. Using a hydrometer, tank water generally has a salinity around 1.023. With hypo, the idea is to drop the salinity to 1.012 (if using a hydrometer, which is not recommended, but I don't have a refractometer. If I did, I'd be shooting for 1.008.) Hyposalinity is considered less painful for the fish than other "cures" (i.e., copper or malachite green) which I have used without any success. This is my first time with hypo, so again I'm hoping for the best. For the most part, I'm following instructions found here: http://www.reefsanctuary.com/forums/fish-diseases-treatments/23131-hyposalinity-treatment-process.html. But be warned, there are a lot of conflicting reports on how to do this. So far, this is what I've done:

1. The quarantine tank is a 29 gallon tank with 3 inches of sand and a biowheel. That's it. I really should have a rock in there for the fish to hide, but I don't yet.
2. After the puffer was sold and out of the QT, I siphoned out five gallons of water from the QT, getting rid of any left over food or puffer poop that fell into the DSB. I made sure to leave enough water so that the biowheel could continue running.
3. I then checked to make sure the specific gravity in my QT was the same as it was in the display tank.
4. Later, after the lights went out in my display tank and my fish were preparing for sleep time, I turned off most of the lights in the house including the lights in the room that housed the quarantine tank to keep it as dark as possible so as not to stress out the fish during the netting and reacclimation process.
5. I then took a plastic bag filled it with water from the display tank, netted and bagged the tang, and brought the bag over to the QT, where it sat in the QT water and began acclimating.
6. Once I acclimated the tang, I let him into the QT and threw a towel over the tank to ensure it would stay dark and less freaky for the fish.
7. The next morning, about 12 hours later, I started the hyposalinity process by going to the store and buying 10 gallons of distilled water.
8. At home, I mixed a gallon of the water with Kent Marine PH Buffer (calcium carbonate) because I read lowering salinity in the tank using RO or Distilled water can cause devastating PH spikes.
9. I poured the water into a gallon jug with an airline valve stuck in the bottom and placed the jug on top of the tank. I opened the valve and started dripping the distilled water into the tank. I'm dripping in the distilled water as I might if I were using Kalkwasser or acclimating a fish.

I've read conflicting reports on how to administer hyposalinity treatment, one saying that rapid salinity change is the best way of killing the ich (which I believe) and one saying that you have to change the salinity slowly so as not to hurt the fish (which I also believe). I followed the latter approach, which called for lowering the salinity over a period of 48 hours with tangs. I figure that the drip method will probably help prevent a PH spike, make it easier for the fish (but not the parasite) to acclimate to the new salinity, and will ensure that the new water will be well mixed with the tank water.

I don't have a powerhead going in the tank. That's also something I've heard mixed opinions about. The plan I'm following from the instructions at Reef Sanctuary, however, say not to have a powerhead.

The tang is breathing a little faster, but I checked the water and everything, including PH is on point so far. He's also eating and swimming around, so it's possible my presence is just freaking him out. Since I started this morning, I've got the water down to about 1.019. I'm guessing that after five gallons I'll probably have to take out and drip in another three gallons to take it down to around 1.012. I'll keep posting progress reports as times goes on. The full treatment takes about four weeks, so we've got a long way to go.