Plantex CSM + B
I am thinking of buying 2 x lbs of Plantex CSM + B Extra Iron or 2 x litres of Flourish. I live in Sydney Australia and the total cost of the fert plus shipping is US$40.50 (AU$53).
The question is, is it worth paying US$40.50 for 2 lbs of fertilizer? I have read great things about it but I can also get 2 x litres of Seachem Flourish for US$65.
The Flourish should last me at least 2 years going by the instructions, ie. 5ml/250ml once or twice per week. I calculated at 20ml per week I would empty the container in 2 years.
How long should the Plantex CSM last?
Correct me if I am wrong.