Bubbler Bucket PH dilema

First time bubble bucketer and am running into problems with my pH.

My bucket only holds about a gallon (which I think is mistake #1... shoulda made it bigger)

I use fox farms grow big & DI water the pH is usually close to 6.3 so I bring it down with lemon to about 5.1-5.3.

Problem is if I'm not home it slowly creeps up to 8 throughout the day. Goes up about 1pH every 2-3hrs.

Help!

Maybe is the airstone I got in there doing that?
Is lemon just not good enough?
Is the bucket just not big enough?
Anyone heard of doing a lemon drip like they do in aquariums with additives?

First of all, lemon juice is not something you should rely on as an effective PH down. Sure it may be ok in a pinch to get you out of a jam, but not long term. Get yourself some real hydroponic PH down like nitric or phosphoric acid, which is way more effective than lemon juice. Secondly, your right, a one gallon bucket is too small. Go get yourself a 5 gallon bucket, larger reservoir = more stable PH. These two simple things will solve your problems and should only cost you about 15 bucks.

i keep my 2 systems ph at 5.7-6.0. Get liquid ph up and down it will dissolve quickwr than powders. Get digital ph meter like $20

What you describe is the PH rollercoaster. pH can swing in amuch wider range than many think. If you try to force it to 5.8 you just create wider swings. Mine runs to 6.5 and once a day I add 1cc per gallon of good pH down. If your swing is between 5 and 7, I'd let it go and what you'll see is the range getting narrower by itself, like a swinging pendulum coming to rest.