it has KNO3 in it yes.. but its quite a low dose solution.
As Seachem instruct: to raise 20 gallons by 0.20 mg/L = 0.25 x 20 x 0.20 = 1mL. So for the estimative index target of c.20ppm (20mg/l) you would need 10ml per 20 gallons.. so for my tank (50g) that would mean adding 25ml every other day which would make a normal 250ml pot last 10 doses, or about 3 weeks.
To use dry powder ferts (PMDD), i need 2.74 grams to do the same dose. 100 grams costs about Â£4.50 you can see how much cheaper it is to use powders.