For the cost of about a litre of it you could get the APFUK starter Kit which will last you years - just need a little mixing its easy IMO. Plus if using CO2 and TNC complete many recommend the double triple dose so x6 standard dose - so litre bottle will not last long with extra dosing as CO2 and maybe higher light 😉I will try TNC complete
Its a personal call for 100l and above DIY saves lots but even at 50l there are savings