Fish are dying 1 by 1 why?

[uwish]

Velvet must be treated with copper, tank transfer does not work with Velvet.

 

[ThRoewer]

Velvet must be treated with copper, tank transfer does not work with Velvet.

Copper isn't reliable on velvet either as it can get used to it. There are even velvet strains that can handle copper levels as high as 1.2 ppm while fish can handle less than half of that.

Formalin dips in combination with TTM is better.
Chloroquine Phosphate is also very effective but not all fish can handle it (pipefish, seahorses and their relatives as well as some wrasses).

 

[snorvich]

Copper isn't reliable on velvet either as it can get used to it. There are even velvet strains that can handle copper levels as high as 1.2 ppm while fish can handle less than half of that.

Formalin dips in combination with TTM is better.
Chloroquine Phosphate is also very effective but not all fish can handle it (pipefish, seahorses and their relatives as well as some wrasses).

What he said. CP is always the preferred choice for fish that can handle it.

 

[ThRoewer]

What he said. CP is always the preferred choice for fish that can handle it.

Though I would strongly recommend using CP in a hospital tank and also do tank transfers to eliminate encysted stages and to be able to shorten the treatment period

 

[alfieferenzo84]

be impossible to qt them. no extra tanks and 15 fish won't do well in a 20-55gal. my 220gal works fine for hypo to treat ick that they had/have.

The sand i have would interfere with copper I'm guessing?

I think the salt got to low and they explains the deaths but could be something else in tank idk. Id be willing to raise salt n do copper but i can't remove the sand or buy another tank...

 

[julie180]

Copper will not work in your DT. A copper treatment tank need to be void of rock and sand.

 

[Louis Z]

I had those same issues with hypo saline treatment. Fish just couldnot handle it. They perished when they got that far. I am not a fan of hyposaline. Velvet would have taken those fish down quickly. My advice is remove the fish and bring them back up to normal salt levels and treat with chloroquine . Start the display tank all over again even if a pita. Restart with QT and prophylactic treatment of ALL additions. I include all corals and inverts and live rock as new additions.

 

[Louis Z]

U can always remove the sand. Lower the water level to dose meds. It takes a lot of medication to treat 220 gal. Hard lesson to swallow. In the future implement QT procedures and prophylaxis to avoid what you are going thru now.

 

[ThRoewer]

I had those same issues with hypo saline treatment. Fish just couldnot handle it. They perished when they got that far. I am not a fan of hyposaline. Velvet would have taken those fish down quickly. My advice is remove the fish and bring them back up to normal salt levels and treat with chloroquine . Start the display tank all over again even if a pita. Restart with QT and prophylactic treatment of ALL additions. I include all corals and inverts and live rock as new additions.

Teleost fish can handle hyposaline conditions just fine for up to 3 months or even longer if you stay above 12 ppt salinity.
If you go too low for too long there is risk of kidney damage due to the reduced urine flow.

If the fish died within two weeks either the salinity was way too low or it was velvet. Velvet actually doesn't have to be visible to be lethal.

Another option would be an opportunistic bacterial infection since bacteria like the lower salinity.