Watering question for ebb and flow

Hi everyone everything has been going well with our second grow. We are now at day 27 flowering and I have been watching the feedback from the plants. My issue is that as we get later into the flowering cycle are the plants supposed to have increased watering intervals? We have been on the following schedule till this point:

water on: about 4 cycles for 10 minutes daily
water off: all the time in between which is about 4 hours between cycles

I am wondering this because some of the leaves on each plant are turning yellowish and some are yellowish brown. I know this happens as the plant gets larger and sloughs off some of its older leaves, but I was also thinking that maybe the plants are doing it because they are using some of the plant food for the buds instead of the leaves since watering could be *scarce. Does anyone else decrease the watering intervals as flowering goes on? Here are some pics.

this site used to be so busy, what happened?

That's a lot of watering. In my imaginary experience, the roots get really dense as flowering goes on, and the plants don't dry out as quickly. thus, less flooding was required, weird I know. Funny thing also, they still used way more water even with fewer flooding cycles late into flower.

In fact, this is why many people fight root rot late in flower IMHO, once the roots get so thick they retain water well, the watering regimen that kept them happy before now keeps the roots wet all the time and boom, troubles.

Just make sure that roots aren't still wet right before a flood cycle starts, and that the plants aren't dry and droopy before a flood cycle starts. Thats the problem, their needs constantly change, definately women.:)

thanks for your advice about the roots. I can tell you that they are definitely not too wet by the time of the next watering if anything they are too dry. It makes sense to only water when they are aired out and 4 hours is plenty of time. I guess they aren't dropping so if it ain't broke why fix it?