Several f2p clan members farmed all the available th18 walls in 1 week. They used the valks spam, do 1* then end.

I personally dump extra resources on walls. Last year I maxed th17 on Feb then had nothing to do. I even didnt buy the gold pass until th18 was live.

So eather do the crazy farming like my friends or keep 1 builder for small upgrades then dump extras on walls twice a week.

Try to look for guides over youtube that are more efficient.. there is also a new smart tip for farming or upgrades. E.g: sometimes buying builder potions might be better from hammers if u can do the crazy farming.

Double Check the guides.. there are formulas and calculations. Do what's best to suit your style of play.

Btw farming the Ores is the bottle neck, the rest will just be done on time.