Did you measure any tank parameters each week to gage the levels then you might have an estimate how long can go before water changes..I stayed at 78 in qt tank. 210gallon tank is at 81-83 trying to speed up fallow period. But ai decided if I add observation period of 30 days. I might as well just run thr full 72days fallow.
I guess a similar question is would you personally just go with the biobrick and put the Pic elbows back. Or take a chance with the rocks. More just seeking your opinion.
Only kinda concern was during qt I change 90/95 % of the water each week. Would fish be find for 3+ weeks without a water change is what I'm kinda stuck on. Granted I leave may 4th through may 28th. So I kinda have a few weeks to trying to semi cycle the tank.
Never treated for flukes. I've heard mention of them but don't really know what they are. Will have to look it up.
Ideally if you could have a barrel or two of heated water at the ready and if a nearby reefer or service is willing to do weekly water changes or so that may be an option?
Otherwise what Wil was suggesting may be your best bet..