UPDATE: 04/28/2020 - Possible velvet survived even higher concentrations... continue reading.
I've had 4 batches of fish this year thus far, and I thought I'd report some findings and my new method. First of all, I've added a diatom filter to the quarantines to handle UNBELIEVABLY cloudy water. I use Instant Ocean and Reef Crystals, both were equally bad. I use DE and it's worked quite well.
My current method:
Copper 2.25-2.5 PPM for 14 days, metroplex concurrently. Testing with Hanna only. Feeding GC for the second week in this tank. I do not treat with prazipro unless I see evidence of flukes, I wait until the second 14 day period in the second sterile QT.
New quarantine for 14 days observation. I treat with prazi during this time, 1.25x recommended concentration 5-7 days apart. I feed GC and Focus mixed for the first week in here (14 days total) for internal parasites.
I don't use spectrogram or any other antibiotic unless needed. You can add it in either 14 day period if needed -- if you do, diatom filter won't be necessary, as spectogram usually doesn't allow for bacterial blooms I have been experiencing. It does, however, sometimes take its' toll on the beneficial bacteria, so watch your seachem ammonia alert badges and have biospira on ready.
Each batch I start fresh, dry out completely OR bleach in-between.
I've also switched to CP for batch 4 because I've had two failed Copper batches. Full disclosure -- I used 2.25-2.5PPM both times
HOWEVER I have been sloppy and multi-tasking so it's possible both failed attempts were cross-contamination with food, hands in tanks, drain hoses, and a myriad of other ways. I am unsure if velvet survived copper or if it was user error. I do not think I cross-contaminated but I am often mindlessly working down there or distracted on the phone. I have also asked
@Humblefish, who said he has had one other report similar, but otherwise we may be the only two.
I've moved to CP recently with good success so far. Fish seem happier, but we will see if it's effective or if I mess up again. CP is difficult to get right now, obviously, but I had a bit left over. I am still pretty confident in Copper Power at 2-2.5PPM, but it is POSSIBLE perhaps that velvet is surviving even higher concentrations of copper. I am unsure.
Because of my working from home, being a kindergarten teacher to my 6 year old daughter, a daycare for my 4 year old son, and a massive uptick in business for me with all of this coranavirus stuff, I am stretched very thin and when I try to multi-task (talk to clients while working in fish room) I have caught myself making silly errors I wouldn't under less pressure and under normal circumstances. In short, I am stretched very thin.
IF velvet HAS adapted to higher levels of copper, I don't think increasing the time in copper will help, and who knows if increasing copper would help. In theory it would. We suspect that the distribution system is using higher levels of copper which again, as we claimed 2 years ago or so COULD mean that velvet is adapting and can survive higher concentrations of copper. I've seen NO evidence of ich after any treatment.
@Humblefish and others will be experimenting further with hydrogren peroxide, which may show promise in the future. But for now, I'd continue course but DEFINITELY OBSERVE FOR 14 DAYS after treatment. It's been coming back within 3-5 days.
@HotRocks @Big G