Hi Loheswaran,
Changing tank water every 8 records is very good. I don't know the Brita filter so cannot comment. However, if you're using distilled water in your tank - strongly recommended - you do not need to filter it if you change the tank water with that frequency.
I recommend using 99.9% pure isopropyl alcohol (IPA). My choice is the
MG Chemicals brand, which is available from Amazon and elsewhere.
Re your questions 1 & 2:
The solution I use includes: ~312 ml (1.3 cups) of 99.9% IPA into ~12.75 liters (3.36 gallons) of distilled water. I also include ~16ml (0.9 tablespoons) of Ilford Ilfotol instead of Tergitol. I'll let you adjust that for your own tank capacity.
If you want to use Tergitol, the recommendation is for Tergitol 15-S-9. That is similar to Ilford Ilfotol.
Cf. post
#102. I don't know the amount as I've never used it.
Re your items 3 - 5:
I do not use a quat because most of them have too much residue as measured with a TDS meter. If you are changing tank solution every 8 records you shouldn't need to worry about disinfecting the solution.
I wash with the above mixture then air dry.
Tergitol 15-S-9 and Ilfotol can leave a residue. With the amount I'm using I don't consider that a factor. Or put differently, I'm satisfied with the clean I get without rinsing. However, I will not say 'don't rinse' - it cannot hurt. The only downside I see is the added time it would take given my setup and the risk that comes with further manual handling of the records. In the future I plan to experiment with automated rinsing.
What ultrasonic tank do you have and which record turner (rotisserie)?
Rgds,
tima