"how much do i need for my pond?"
MICROBE-LIFT PBL Professional Blend Liquid and MICROBE-LIFT SA Sludge-Away, dose by surface acre, not acre-foot.
Standard professional treatment rate - PBL
Initial dose
Approximately 12 gallons per acre
Follow-up
2–2½ gallons per acre weekly for 3 weeks
Maintenance
2–2½ gallons per acre monthly
Standard professional treatment rate - SA
Initial dose
3 gallons per acre
Follow-up
1 gallon per acre weekly for 3 weeks
Maintenance
1 quart per acre monthly, adjusted for muck depth
The published professional protocol lists PL at 10 gallons initially and 2 gallons for follow-up. Since PBL is approximately 80% PL, the practical equivalent is about 12–12½ gallons of PBL initially and 2½ gallons thereafter. The manufacturer’s startup kit also supplies 3 gallons of PBL for a quarter-acre pond, which equals 12 gallons per acre.
For heavy bottom muck, the startup-kit rate for SA is considerably stronger: 2 gallons per quarter acre, equivalent to 8 gallons per acre. That is more of a restoration or bio-dredging rate—not ordinary maintenance. The standard professional rate is 3 gallons initially, followed by 1 gallon weekly and then 1 quart monthly.
Apply evenly across the pond, concentrating SA over the muckiest areas. Start after the water is consistently above 50°F; aeration will greatly improve performance.