Thanks for the advice. Just a few questions.
I just want to confirm if its recommended to TTM only if Ich/other diseases are present or i should do this method from the jump even if the fish are healthy?
TTM can be used both as a treatment for a present disease, and as a prophylactic step, just in case. keep in mind it is really targeted at ich, due to its life cycle. there are other things that it does not handle.
Wont the constant move from one tank to another cause more stress on the fish?
it's not as bad as you might think. key here is having the new tank you're transferring in to matching the tank you're transferring from, salinity and temperature being the two most important parameters here. the tanks are usually fairly bare by design, with some PVC hiding spots, so catching the fish should be fairly straight forward. i use a medium sized plastic colander with a handle. it doesn't hold on to water like a net, and its smooth surfaces and polished holes help reduce the chance for injury to the fish. it is also just the right size that i can loosely place a 5 gallon bucket lid on top, to help mitigate the risk of the fish jumping during transfer.
In the TTM sticky, it says "If powerheads/HOB filters are to be used, a thorough (24-hour) soak in bleach solution is recommended". Would i take the media out of the HOB filter or keep it in when I use bleach?
if you're going to do TTM i would ditch the HOB filter entirely and instead use an air pump and air stones that you can just throw away after you transfer (this includes the airline, anything that got wet). makes things easier.
i would use your HOB for when the fish are done in TTM, and you want to let them hang out in a holding tank for a little while.
here's my basic regimen:
new fish comes in and goes in to the first possible TTM tank. if the fish is eating well and seems happy, i will begin the TTM process the second day after their arrival. if they're not seeming to do well, then i will let them hang out a bit longer before i start transferring them, until i can get them situated and eating. during this time i do regular water changes and use an ammonia locker like AmQuel or Prime to help keep the water quality up. i siphon out any uneaten food daily and replace with new water.
during TTM, i continue to siphon out uneaten food once a day, and replace with fresh water. when i remove the fish to transfer, i place bleach in to the old tank and let it sit for about 12 hours. then i drain everything in the old tank out, wash it well with fresh tap water, dry it with some paper towels, and let it sit to air dry for another 24 hours. i throw out the air stone and air line.
the night before the transfer, i get the cleaned tank and set it back up, filling it and getting the heater dialed in. i add in the pvc sections, and a new air stone and air line, and get the bubbles going.
once i have completed the TTM method i place my fish in to a different system to rest, relax, eat, and be observed for anything i might have missed while in TTM for usually 2 - 4 weeks.
you have some options here.
i am fortunate enough to have the room to keep a second, fully cycled, tank with skimmer, live rock, ATO, etc... that i have designated as a grow out system.
you could also use your HOB filter here, or use an uncycled tank, and just keep up with the AmQuel or Prime, siphoning uneaten food, and daily water changes to manage your ammonia.
then after you've had sufficient time to observe and make sure they're eating and free of any other parasites or disease, in to the main tank they go. i usually use an acclimation box so that new arrivals can safely get introduced to my current crew.
keep in mind that none of this is necessarily required, and that you're free to design your own mix of elements in your QT protocol to suit your needs and space. not everyone has the space i have, and any QT protocol is better than none. mine can be a decent amount of work, but i feel that is is robust and offers me a high degree of risk mitigation for introducing pathogens, which is why i stick with it.