I've used DE in the animals' water trough. It's not noticeable, increases their health through deworming and added minerals, and actually inhibits algae growth. I cleaned the trough half as often with DE in it, and even when I did there was no noticeable algae.
Though this thread is very old, I am also so here goes.
Regarding Paul's comment about Basic H (not 2H, I don't know about it) not being organic, we operated a certified organic livestock operation until my wife passed in Feb, 2017. We were certified by Ecocert Canada and my wife submitted sufficient evidence of the purity and organic status of Basic H that Ecocert approved it for worming our cattle.
I deeply appreciate this post because I am sure that is how my wife wormed our livestock guardian dogs and house cats. However, I did not know that and vets succeeded in pressuring me into worming them with allopathic pills. One of the dogs got very ill. I won't nor, thanks to this post, do I need to do that again. I have lots of Basic H left. (-:
BTW, insofar as Diatomaceous Earth is concerned, we were a distributor for PermaGuard for a time. I put together this page on DE that many said was the best single source for info on DE on the web. Here's the URL - http://www.gaia-tree.ca/DE/PhoebeDE.html. Note that any links to Pinnacle Farms won't work.
Basic-H is an amazing cleaner. I'm just about out with a quarter bottle left - about two years supply - so last week I went to get more from my local Shaklee's dealer to buy some more.
I didn't end up getting any because my dealer says that the manufacturer changed their recipe recently and as my Shaklee's dealer is also famous in town for their eco-friendly cleaning services, the dealer can no longer carry the Shaklee's brand. I contacted a few other dealers in town and they are also discontinuing that line due to the recipe change.
I haven't done the research myself, but the general theme I got from talking to these people is that the product is drastically different and no longer as non-toxic and/or eco-friendly as it used to be. A word of caution: if you use this product for your animals, research the new recipe FIRST! I'm hearing stories that it is no longer safe for internal use.
But like I said, this is hearsay. If true, I'm very sad because Basic-H was one of the few cleaners I would spend actual money on because 1) it didn't hurt my skin, 2) it lasts forever - the less you use, the more it cleans and 3) because it lasts so long, it was the most affordable product I found.