Keith, the problem with lawn or garden fertilizer is that you do not want any potash in your water. Even a percentage that is at 5 can be detrimental. Normally most ponds have plenty of potasium and no additional potasium is needed. That is why Trophy Maker, or liquid fertilizer contains no potash. Liquid fertilizer we use is 10-31-0. It is just highly concentrated. I would reccomend that you stick with fertilizer that is approved for aquatic use.
