when I transfered from my 180g to the 300g...both my 4 inch YT had to housed in a spare 90 gallon...water chemestry of that tank is just a tad better then the toilet bowl...the tank was housed in the gargage with 2 T5's no temp control...and it was topped off with a garden hose every so often
When the 300 finally cycled...(7 weeks) I saw my YT was about 50% covered in black ich...so I fished them out and put them in a bucket of RO and added some copper into the bucket...NOT the tank...fresh water/copper dipped them for 8 mins and introduced then into the 300g
Under the MH's the black ich's are now white specks and either fell off within 30 mins or the cleaner shrimps cleaned them...
It's been about 9 weeks...YT's happy as a clam!
Good luck!