noticing that you say that your on a tight budget, visit your local pet shop and get some hemp seed, read up on how to prepare it safely and properly and it will be useful in two ways:
provided the weed you was talking about is relatively near the bottom, and also if your lake contains roach and other such small fish, find a weedy spot that you want to fish, then spod out a few generous spod fulls of hemp, plain is fine ( extremely cheap making your own), around that weedy area. Provided the silvers are there and feeding, they will clear all the bait, but will take a relatively large amount of the weed with them too. clearing a nice spot to fish/spod over.
Also hemp is probably the best thing to use as a base for a spod mix. Having prepared your own, now you can add other ingredients, ones that i have tryed and that have worked for me are:
sweetcorn
maize
boilie - chopped,whole or crumbed
pellets ( have to be added right before use as can make mix stodgy and then harder to digest )
groundbaits
tiger nuts - chopped or whole
tiger nut flower/meal
chilli powder
tuna
bloodworm
maggots
casters
condensed milk or coconut milk
groats
pigeon conditioner
maples
tares
nesquik banana milkshake powder
peanuts
liquid attractants
etc.......
chop and change to see what works for you, try and use something different for that edge over other anglers
i hope that helps, good luck