Can you Equalize Flooded 12V with Solar over a a few days?

Equalization can be continued on the next day, if needed, not loading them in the interim is a requirement , however it's best to EQ when required. By this I mean using a hydrometer to check the specific gravity of the electrolyte, if all the cells are according to specifications there is no need to perform an EQ. Lightly used batteries may require less EQ, than recomendations call for, specific gravity is the bench mark method of determining when it's actually required. Get a good quality glass type hydrometer, check the SG before making the decision as equalization is actually hard on batteries. 

MontyYoung said:

My understanding is the amount of wattage/current needed is small to perform an EQ, like C/20 or less. Is this true?

Since equalizing starts with a fully charge battery, that basically won't take more than 1-2% of it's capacity at normal voltages, it usually only requires 5% of your battery capacity or less. So yes.

You can certainly equalize on solar alone! It may be a misconception that you can't because people often use timed absorb cycles. I usually pick a couple sunny days even this time of year, when days are short and I'll try to reduce loads at night as much as possible. It's very easy when we get 2 sunny days when I spend the night in town. Then by noon my batteries are fully charged and I can start a maintenance equalizing cycle. 

Corrective equalizing can go on for days, and in that case, a generator is a bit easier, but I've never used one with my batteries and have been dealing with it okay.