Rye starter + buckwheat starter

Toast

My rye starter doubles and is filled with air pockets at that stage.   

I don't use anything by rye flour and water, starting out with 6.4 ounces of rye and 6.4 ounces of water.

On day two and thereafter, I use 3.2 ounces of the starter, 3.2 ounces of whole rye, and 3.2 ounces of water.  By the third day it has to be fed twice a day.   This is using Arrowhead Mills organic rye.  I don't get the same results with Bob's Red Mill organic rye, so I quit using it.

I've no knowledge of buckwheat, except that it contains no gluten.

What brand of rye flour are you using?

Why not try feeding it every 12 hours?  

I find that my rye starter is thicker/stickier than my freely bubbling white flour starter, even though both are made using equal weights of flour and water(i.e. a 100% hydration).When I stir it down, I do find it has plenty of bubbles distributed and actually,I think it has risen-I just miss it since I feed it at night and go to bed.

If your starter smells yeasty, I would continue to feed it once or twice a day for a few days and then try baking with it. If it is getting hootch on it, it's hungry and needs to be fed more or more often.