Sorry folks, but the experience (limited as it may be) I have had in my tanks does not match with yours, or your logic. The reason I have become such an advocate of most of Walstad's methods is because it works for me and because it is ecologically sound.
Algae? Had it. Started to get bad, bought an SAE. Did nothing but added bio load to an already stocked tank. Did as Walstad suggested, added Duckweed, covered the back of the tank with cloth to filter (not completely block) the window light. Presto, 1-2 weeks the algae was reduced to very light film on the remaining window side of tank. Very easy to scrape off, not a big deal. Bumped up to 30w from 20w for ~3 watts/g, no increase of algae, in fact the opposite. Also, I run my lights for 12-14 hours a day *gasp*. Last I checked the sun was up more than 10 hours in tropical and sub-tropical regions where most of the plants we use in our hobby come from (yes I realize the intensity changes throughout the day). Following the success I had with the aforementioned tank, I have successfully controlled algae blooms in 3 other tanks (all moderate light) with the duckweed/light filtering method.
Rex, seriously, that is a cute analogy with the bathroom, but c'mon you're a smart guy. Plants clean the water and to some extent the substrate. And they are darn good at it too. Why do you think my tank doesn't have an inch layer of crap on the bottom? You'd think I'd see it, it's white gravel for carp's sake. Organic matter settles and decomposes. Organic matter is made up of Carbon and a host of other yummy nutrients that plants use to grow. They use duckweed and water lettuce to clean water in waste treatment plants. To take your analogy one further, would you drink water that you took a dump in a week ago? Heck yes you would, and it may be because you trust plants to help to clean it (OK, you probably wouldn't because I think you mentioned you have well water, but the reasoning still stands). You guys all love plants, then why the heck don't you give them the credit they deserve? Holy cow, we force-feed our plants CO2 and they gobble it up, turn it into oxygen, and ask for more. If you trust plants to clean the water of toxic gas, why wouldn't you trust them to suck up decomposing organic matter like it's their job? It is their flippin' job, this is what plants do in nature, they clean the air and water and dirt of crap. Manure anyone? Plants in nature are the only thing keeping us from having to wear fishbowls on our heads hooked up to an air purifier. Did you ever consider that the reason you have to do weekly water changes is that you are giving the plants nutrients (ferts) that they normally would be sucking out of the water and substrate to keep it clean? It's like me hooking up a CO2 canister to a trees that fed it intravenously, and wondering why the smog was so bad lately.
I will say this again, I have not lost a single fish in this tank since I set it up in January. This is not the case any of my other tanks. My fish are very important to me, I treat them as I would want to be treated. If I didn't think the water was clean enough for me to drink, I wouldn't put my fish in the water. Keep in mind please, that I do weekly 20% water changes and gravel vac my other 3 aquariums religiously. I do this because I know the plant load is not enough to keep the water safe for my fish. If I could retrofit these tanks without fear of stressing the fish out, I would do it in a heartbeat.
Anyway, rant off, for now. But some of you folks really are frustrating. Do everyone here a favor and open your minds a little to the natural side of this wonderful hobby. That's why I'm doing this, and why I want to help others to do this, so I can embrace nature and capture a tiny slice of it for everyone to enjoy.
Peace, Love, and CO2...
