Tough to see in the videos, but for a split second i saw the fish's pectoral fin - pretty evident it has ich.
Most amine-based copper products need to be dosed for 30 days at 2.25 to 2.5 ppm.
Treating it in-situ is not really possible once the disease reaches a certain level. It may be past that level now, but if that is your only alternative, you could look into "ich management".
Here is my protocol for ich management. Please understand that I am NOT presenting this as an optimum method for controlling ich, just putting it out there for people who want to try it. Also, do not pick and choose which items you want to follow - you need to go with all guns blazing and use them all.
“Ich Management” Because many aquarists mix fish and invertebrates, they are ill-prepared to then treat for marine ich, as the two best treatments, amine-based copper or hyposalinity, cannot be used with invertebrates. A popular technique has then arisen, “ich management”. It is popular not because it works well, but because it is an easier alternative. Be forewarned, it often fails if applied during moderate infections. The reason that it exists as a technique at all is because people find themselves in situations like this and are desperate to try anything.
The basic idea is to reduce the infective propagules (tomites) of the ich parasite to the point where the fish's acquired immunity can fight the infection off. This is done through a series of techniques for stress reduction and tomite limiting. Unfortunately, the ich tomites themselves cause stress to the fish, so if the fish have more than 30 or so trophonts on them, the method often fails.
1) Install a powerful UV sterilizer on the aquarium.
2) Ensure that the fish's diet and water quality are the best you can make them.
3) Keep the water temperature close to 78 degrees F.
4) Siphon off the tank floor nightly to remove as many tomonts as possible.
5) Employ strong filtration to trap as many tomites as possible.
6) Try a proprietary "reef safe" marine ich medication. These rarely cure ich infections on their own, but some may have benefit when combined with other management methods. Avoid the herbal remedies, focus on those that contain peroxide salts. There is, however, some evidence that using peroxides with UV does not work, as the UV can break down the peroxides.
Jay
