Actually you have been relatively lucky. Usually tail rot and dropsy would be taking your fish apart by now with your feeding regime. Mother Nature must like you. ;) She has been much more gentle than what she usually is when we overfeed.

Your guppies should have all their food cleaned up in a minute or three. The books say five minutes, but that is too much for browsers like guppies. Guppies have relative small stomachs and somewhat long intestines. That suggests that they are an omnivore, which takes a fair amount of vegetable material. The same amount of food in three feedings as what we used to feed them in one would be better.

One book, as a general rule, suggested that one should feed a fish an amount of food about equivalent to the size of the fish's eye. That is often incorrect, but it is an interesting way to make us think about how much we are really feeding them at any given time.

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This is not an easy read, but
http://www.fao.org/docrep/X5738E/x5738e02.htm

will give an over view of the digestive systems of fish. I was struck by the observation that carnivores had more enzymes to digest proteins, but they also have some enzymes to digest plant material and even carbohydrates! The omnivores have enzymes to digest proteins but not as many as do the carnivores. They do have more veggie digesting enzymes. Carps seem to have the most

http://www.fao.org/docrep/X5738E/x5738e13.gif
is a drawing of the guts of four types of fish.

The top one is a pike or some sort of salmonid - in this case a rainbow trout. Not much intestine. The fish they swallow is digested in the stomach - disassembled and reassembled as pike. ;)

The second digestive system is that of an American catfish (channel cat), which eats meat but also some plant material.

The third system is that of a common carp. It has a long intestine, almost no stomach. In the throat are a set of "interdigitating pharyngeal teeth" which chew up the plant material. They seem to eat small quantities of food at one time, much like wild guppies. (This should also be a hint as to how aquarists should really feed their koi and goldfish too.)

The last system is that of a milkfish, a marine/ brackish, even sometimes freshwater filter feeder. It is listed as a planktovore, straining all sorts of microscopic creatures out of the water with its fine gill rakers. Some of the stuff they strain out are tiny plants, some are tiny animals (like Daphnia and brine shrimp) and some are protists which are animal like, but also have chlorophyll. The stomach is essentially just a tube. "The pyloric end of the stomach has thick, muscular walls and is usually described as a gizzard." It grinds that stuff up for the long intestine to work on.

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At the rate you must be feeding, 20% daily water changes may be too little. :) In reality I have a great lazy streak and would rather tell others to change water than do it myself (though some water has been changed down and a couple of 5 to 10 year old tanks are being torn down and restarted today). Being lazy or maybe time challenged, I'm pretty careful about not overfeeding because then I have to come back that same day and siphon that mess up.

You are exhibiting a wonderful enthusiasm for your fish. That makes your comments a lot of fun to read. But as with the skilled athlete, you need to play under control. You have already discovered that you don't want to medicate (i.e. poison) your tank without learning what it might do. You also need to read about any new fish (i.e. coldwater super poopers like black moors) before you get one. You also need to learn what feeding is all about.

You are doing the fish-related things in the same way that you are writing log submissions. I'm sure your high school teachers ask you to double-check what you write and proof read them. (I think how a person writes their responses on some job applications is more important to the potential employer that what is written.) An easy thing to do here is to highlight what you wrote, right click on your mouse, copy your text and paste it into MS Word or whatever you use for word processing. (NONE of us ever see all of our own writing mistakes.) Do a quick grammar and spell check. Adjust your Guppylog submission accordingly. That way you will spend more time proofing and correcting your posts than I have. ;)