How much fluid do you guys use?

I generally cover the entire surface of the record so one does not see any grooves but I wonder if I'm wasting fluid.
it depends on what cleaning solution is being used, but in general I don't use that much. if you use a puddle about the size of a quarter that should be plenty.
I agree with Dan_ed that you are using a bit too much.
I think I use "about" 1 teaspoon. (Basically, I put a thick line of fluid extending from the record edge to the label, and then I spread it around the record with the DD cleaning pad, and then I scrub the record a few times in both directions, longitudinally with the grooves of course.)

My two cents worth.
Have you tried using more fluid? I've found using more than you state works better but I'm wondering how much I can back off.
Personally, I use even less cleaning solution since I started steam cleaning.
I guess I'm guilty of over using. I use about 2 tablespoons...then spread around with a last brush...

(I use premier 1st, the record research deep clean, then wash)
I put mine in a spray bottle and use 4-5 sprays as the lp goes around on the 16.5.
I get a lot of LP's which have mould but are otherwise near mint. The mould is usually on the first few tracks where the the vinyl was more likely exposed to the air when stored. The mouldy sections of these LP's sound noisy.

I use AIVS and like to soak my LP's for ten or more minutes as they recommend. This gives the enzyme solution more time to work on the mould. To do that I have to cover the grooves and ensure that the fluid doesn't dry up. That requires a lot more fluid. I lay a thin bead around the entire LP. Using a mofi brush, I found that the I was using more fluid because the velvet brush soaked up a lot itself but the AIVS brush minimizes that by spreading the fluid very evenly. I find that my LP's sound a little quieter after a soak than just a quick clean.
When I use the Disk Doc fluid, I only use a teaspoon or so. However, when I use MFSL Plus, I use enough that as I brush, the fluid will cover the LP.