Water Lily Question And Planted Tank Question

hey all i am planting a 55 gallon right now and i have a couple questions! first, is i have two aponogeton plants and 4 onion plants, they are grwing great! one plant is growing a stalk with a bud on the end and it grow half an inch an hour but i use root tabs, but instead of implanting them into the substrate i just drop them in and let the nutrients dissolve into the water. is that fine? it seems to be working. 
 
question 2. i bought 3 water lily bulbs but i read into it and it says they might be invasive... there are a lot of pages and opinions but its hard to find answers, can you tell me what the extent of this is? thanks cuz i really like the way the look! 
 
ps. i also wants pennywort eventually and flame moss. btw i have a java fern and anubias. heres a pic of last week

lefty07603 said:

 but i use root tabs, but instead of implanting them into the substrate i just drop them in and let the nutrients dissolve into the water. is that fine?

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I'd plant the root tabs and buy liquid or powdered ferts for the water column.
Two of the main reasons for that would be - For the size of the tablets, it'll cost you more money putting enough of them in to get the same results from a liquid. The second would be that some of the better root tablets contain small amounts of ammonia - Not a problem when they're buried away, but not desirable if you're regularly putting them in to the water column.
 
IMO

okay thank you! ill get some flourish! and anyone else have experience with water lilies?