Cheap easy way to lower ph?

So I did a transplant from MG soil to hydro bucket DIY bubbler. Me being my first grow is a noob and didn't check the PH level until now(5 days later), it's 7.0....
So that explains why it looks like shit.

Any easy cheap ways I can lower it now? I heard multivitamins will do the trick?

Any ideas and suggestions will be greatly appreciated.

If this hydro bubbler don't work out, i'm going to go back to soil (regular lows earthgro, mixed with perlite) using foxfarm trio quarts as nutes....

Hi Locedd,
one way to lower pH is to buy some citric acid from a
Health Food store so you know it's organic. Two fingers width amount
of citric acid in the bag will last you for 2 grows or more ! It changes pH
with just a pinch in 10 gal. bucket of water. So this stuff goes a long long way.

You can even use it in food and drinks for your own health benefits.

Zeff.

i used a lemon one time to lower until i went to store the next day.