Guinea Pig Questions?

Ok so I kind of got off schedule for a few months an havent been caring for them as well as I should have but now Im making a new schedule an also making them a playpen some questions I have for other guinea pig owners are,I change my guinea pigs water everyother day? is that ok? before when I had more time & also didn't go out as much it was daily,now I do it everyother day unless its hot in the house then Ill do it everyday until it gets chill again..another thing is how long should a 96oz bag of hay last? an how long should pellets last? the pellets usually last me a month as for the hay I usually get a 48oz bag that lasts a month also an since the 96oz is twice the size I figured it should last at least 2..also I feed them veggies or atleast try to daily..usually 1/2cup to a cup and once inawhile more is this a good amount? the veg I feed them usually consists of romaine lettuce,green bell pepper,an 1 or 2 other veggies. sounds good? be honest =/ as for their playpen they havent really been out there cages for a few months due to being kicked out my house,packing everything an have been to lazy to unpack again so my whole room is crowded but once I set up there playpen I was thinking 2hours each aday? since they dont get along should I try an put them both in the same playpen an see if there differences will pass there? another thing whats a REALLY an I mean REALLY cheap bedding that will NOT cause any harm to them..I use carefresh but Ive gone a whole month without cleaning there cage due to not having the money to buy it..an ik some of you may say give them to someone who will care better for them but trust me there is no1! they have some health issues that only someone who has had them for awhile like me would know how to handle them..anyway what isa good/fair super cheap bedding? easy to clean? an is it ok if I use a folded blanket under the playpen when I put them in there?? please help answer any questions as well as you can..TY