You may be talking about water hyacinths or water lettuce (a few other possibilities). They are both rapid spreaders (invasive in warm climates). General water plant fertilizer tabs like you can buy from aquatic plant sellers would probably work by just dropping them in the tub with them. We like hair brained ideas for making money too. Sounds like you've got quite the set up for indoor growing. I am trying some hydroponic vegetables this year.

Thanks Trelby.

Unless you are doing hydroponics I dont see why you would spend all that money .... Can you absolutely not have any outdoors? Water plants as we call them can be grown in anything that holds water except aluminum (and copper too if Im not mistaken I honestly cant remember at this very moment). You can use kiddie pools for about $6.00 a pop. Or Rubbermaid tubs. All you need after that are seeds/plants and fertilizer. Now if you keep these plants indoors then wow yeah. Just so much money. But it sounds like you are going hydroponics style. Yes and that is costly. And basically.... any plant can be grown through hydroponics *S*

Dendy,your right I do want to propogate them hydroponicly.
I belive that in hydro the plants will root faster.
The reason for the indoor set up is I want to start them in the fall and grow them through the winter.Come next spring
they would be transplanted into soil and gradully brought
outdoors,ready to sell(hopefully).Think it will work???
thanks.