Things were kind of hit and miss today. Alex was having trouble staying awake earlier in the day and I felt very tired as well. We kept adding the extra nap at the two hour mark for a couple of periods and now we are feeling much better.
We also tried shortening the nap time to 18 minutes. This results in us feeling much more refreshed when we wake. I think we were getting past the REM phase and burrowing into deep sleep before we woke so we felt groggy. When that happens it can take hours before we feel alert again.
I'm beginning to think we might need to allow a longer nap every now and then too. Something on the order of 30-45 minutes. The tricky part is that this extra time needs to be on one of the naps that skips the REM sleep at the beginning and goes straight to deep sleep. This is all speculation of course, and the only way to figure it out is to experiment a bit.
We are still going to stick as closely to the normal 4 hour schedule with our new 18 minute naps until at least the end of the second week, maybe the third. The early experimentation is only born out of frustration.