Keep on scooping. The more organic debris you remove, the faster clearing the swamp will be. The water sample was taken after the pump was on for a while, so the water is mixed, yes? Because snowmelt and rainwater can sit as a layer and you don't want skewed test results.
That said... With no CYA left after winter and a swamp, I worry that Ammonia may have formed from the breakdown of the CYA. So before you dive right into the SLAM process, take a few minutes to check for Ammonia.
1) Raise FC to 10 using bleach. That's 215 fluid ounces of standard 8.25% bleach. It's close enough that you could just dump two full 121 oz jugs in.
2) Retest FC in 10 minutes. If FC is 5.5 or less and CC is high, you probably have Ammonia. It takes massive amounts of bleach to neutralize it if you have it, so it may be cheaper and faster to drain some water and replace it.
Post the results if that happened and we'll walk you through things. If FC is close to 10, then you go to the regular SLAM instructions.
Perhaps in a few days you can check CYA again just to ensure it is still where you programmed it to be. Have a nice day.
