Double sack crawfish burner ?

2.5 bags of Louisiana powder
1/2 16oz bottle of Louisiana liquid

Get 2 bags of powder for next boil and start over.

First thing, measure your water with a 5 gallon bucket. Fill the bucket up twice, dump in, and note where your water line is for 10 gallons for future reference. Most big brand seasonings are made for 5-6 gallons of water typically, but I agree you don't need to double. In my 120qt pot I usually go 1 full bag of a local store I likes seasoning and 1/3-1/2 of a spicy zatarains container. Feel free to add liquid if you like but I find I don't need it with those ratios

Here's something that we started doing and found great success. We boil very often, like 20+ times a year.

When we are starting the water and will just have fixing in the water for a bit (because things like the potatoes and all need to boil for longer than the crawfish), we put only half the seasoning that we will use once the crawfish and everything is included. We boil those first fixings for what I would guess is about 10 minutes on a very low roll boil (wait for the water to come to a boil before adding the fixings, don't put anything but the lemons in the pot until the water comes to a boil).

At this point, we remove the fixings and get the water back up to a good rolling boil and add the remaining seasoning we intend to use. Put only the crawfish in and wait for the water to come back to boiling after the crawfish are added before putting the fixings back. Then we "boil till they peel good and soak till they taste good." Take the fixins out after soaking for just a bit and if you can try things in the fixings, even better.

We purposefully over season the water and control the taste by removing when stuff tastes like we want it to rather than timing things.