The one thing I don’t get is why only the hippo tang has it and no other fish... but you are right I need to pick a method. I’m going to raise the salt content and the temp a bit. That should help.I don't know of any medication to treat the heavy hitters (brooklynella, velvet and ich) that you can treat in your display tank (DT). You can try the humble.fish forum just to clarify if you are looking for fish disease experts asap.
Forgive me if I'm telling you stuff you already know, but I'm new to reefing (little over a month) and have already faced brooklynella in my DT after adding my first two fish ever and this is what I know. From my understanding if you have fish disease in your tank you have two options, removing the fish and treating them separately in a quarantine tank so you can dose any medication you want or leaving them in the display tank and accepting fish disease and practice disease management. From the looks of your tank if your fish are recovering you could feed them frozen foods keep them healthy/fat and accept fish disease for what it is. Throwing in a UV sterilizer will help keep some free floating diseases in numbers that hopefully your fish's immune system can fight off and try your best to keep a good biodiversity in the tank. There are many ways to keep a good diversity such as Paul B's method of feeding clams (gut bacteria is good) and adding mud/other stuff. Link here to Paul's thread, tons of good info on the other side:
I was 50/50 on disease management vs eradication after my encounter with Brook and ultimately chose to remove my sick fish from the DT and fallow for 76 days to kill most fish disease and treat my fish separately in a quarantine tank and reintroduce them after a fallow. I currently have 4 fish, one of which had flukes which I treated prazipro in a observation tank w/ live rock sand and coral. Prazipro is one of the few medications I know of that is reef safe but it does not treat all fish diseases and didn't require me to put fish into a sterile true quarantine/medication tank. Some of the other medications have different additives that will leach back out of the sand/substrate and cause issues with your coral such as copper. Unfortunately there is no guarantee putting your fish through quarantine and proactively treating with medication will eliminate all disease as sometimes fish are placed back into the DT and show signs of fish disease after fallow/treatment.
Ultimately we just have to pick one and stick with it as true as we can and hope for the best.
Here is a picture of my observation tank/quarantine setup. Just a cheep tough homedepot shelf with a 20L tank I can observe fish in before they enter my display tank for one month. If they show sign of fish disease I will remove them and place them in the sterile 10G and treat with medication until they are healthy and then reintroduce them. I have medication on hand for the fish diseases I know of + a air bubbler for diseases that effect breathing.
I got another one and it ended up showing the same thing. The house is at 69f.I noticed you were having trouble measuring your salinity, did you ever get that figured out? I had issues where my refractometer was cold from the winters here in NY and it requires me to recalibrate with RODI water before I use it every time or I could risk my mix being wrong. I also use a direct salt addition calculator that allows me to weigh the salt and add it to a known volume and get near a specific value of salt which helps me get in range.
Good advice. The thing is I was told the other way with salt. And the funny thing is when I run it high salt I don’t have sick fish. This is the first time in over 10 year I have had fish get sick with out a change in the tank other lowering my salt.I'd shoot for 1.023/1.024 and consistent 78 degrees if possible. Don't lower your salinity more than .001 within 24/48hrs or you could risk killing your tank. I know people run high salinity but I am not aware of the value. 1.023-1.026 is what I see generally recommended. I prefer 1.023 to give me some room if my ATO fails my salinity doesn't sky rocket due to evaporation.
Quick edit: I would ask in Paul's thread about lowering salinity and it's affect on a tank like yours (capability of fish to fight disease/disease population etc) if you decide to lower it. I don't know of very many people who run high salinity and as of now your fish are relatively healthy.
I believe I also saw that lower salinity helps keep lower the free floating stage population of some diseases.
Good point. He has a bad tendency to hide and in process scratch himself. There was a time I thought he was not going to survive because it got infected. You can see the spot it left on his tail area. But he survived. Hope he survives this one. And the odd thing is that the other fish are not sick.I may have confused the lower salt helping fight disease with allowing the fish to breath better with diseases that affect the gills, I've taken in a ton of info in the last month LOL. Just about every hour I'm outta work I'm researching all this stuff. I'm a fellow military vet and can't let **** go sometimes =D
Rapid changes in salinity/temperature as well as external influences tend to stress fish out and will show fish disease if they were previously fighting it off within the tank with a healthy immune system. Tangs tend to be the worst and are quick to show ich after leaving the LFS. Also tangs have a thinner mucus coat than other fish such as wrasse and clownfish.