I played a public on hard with this build not really planing on killing fruit that much.
It worked out pretty damn well.

Killed 320 on hard mode.

Build is simple

Get level 3 light fire and earth asap then get +2 pures so 4 total pures at end.

Place quarks on long path areas like center and entrance long path.
Place 4 lighting towers on center long path far right of it so they hit the far lane as well.
Use forge towers to amp the damage of everything by 120%
I dont get any money towers maybe you could if you wanted to.
I choose fire pures not sure if they are the best or not.

Quark towers are REALLY good in the early stages of the game if placed on long path areas in middle.
Be careful on earth waves early-mid mainly the spider one.

I bet if you got interest early instead of 2 pures at end you could kill quite a bit of fruit in very hard.
I might test it out later on.

waht does tat mean

"get level 3 light fire earth asap"

so rush for 9 elements?
if ur having 4 pures at the end, how does the accounting work for getting pure essences? how many do u get automatically?

pures are for later on.
how do u survive to that point? whats the best way to go? quarks first?

so
L,E,F,L,E,F,L,E,F? in that order?

or LELELE FFF LE?
whats the order!

Fire Light earth in that order seems to work best in public so
FEL FEL FEL pure pure and you get 2 free pures.

Light first probably would work best in single player.

you don't really need to use any element towers before you get all 3 elements so order does not really mater too much

Earth is the least important because forge is not very good until its level 3.

Placement is really important.

I'm new to the game and I'm a noob, could you explain what do you mean by "long path"? Is it long for creeps to get to the second pass (slash on numpad) or is it long for creeps to stay under fire (position 5 on numpad)? And what do u mean by "you don't really need to use any element towers before you get all 3"? I suppose you suggest to get all three elements on level 1 and start by getting quarks for example? Thanks in advance to anyone who will answer those noob questions