And that raises a key point. How many of us are prepared to do that?

There are accounts of naturally occurring pools in wooded areas (where channelization and drainage systems haven't yet dramatically lowered the water table.) It was estimated that those ponds, really just the upper extensions of said water tables, experienced over 90% daily water changes.

A lot of our aquarium fishes come from headwater areas. We collected some great southern red belly dace two summers ago about 15 miles south of here off of I-57 in a more controlled and "industrial" stream but it was still something of a headwater. Those headwaters still in a natural state (and even the four pretty major rivers beginner as run off from drainage tiles from farmer's fields (around Champaign, IL) have got to be contributing nearly 90% new water daily from rainfall and the water table.

Now the surrounding waters and the soil in and near the ponds probably harbor even more active microscopic creatures than most aquariums. I think it is David E. Boruchowitz who has most effectively promoted the idea that the entire aquarium is really the "biofilter." That mechanical gizmo in a plastic box is just part of the process. And several people would chorus, yeah, but that is why massive water changes must be quick, smooth and efficient, because not only does one absolutely not want the regular "filter" to stagnate (maybe killing the beneficial bacteria or going anaerobic) but that as much as possible of the tank (gravel if any, plants glass bottom and sides, other structure... should stay wet in order to do this.

In the most recent AKA Journal, one of the most talked about articles was Jack Heller's tour of his fairly automated fishroom. That he could use a system of valves and PVC pipes to partially drain most of his tanks to a certain level, start a pump a pump to raise water out of his three 55-gallon water holders, refill and treat the water needed to do 15 to 20% water changes every two days left me dazzled and jealous. And he did that within an hour! ;)

Jack, whose fishroom I know you must have been in several times, could do those changes every day, But (for some odd reason) he doesn't.

Up here in the 1980s and early '90s Joe Gargas raised a lot of wonderful discus of many strains. I was dumb-founded to drop by one afternoon and see adult pairs of discus on their sides in just a little water in the 20-gallon breeding set-ups. He drained fast and filled pretty fast using a system of holding "reservoirs" and a pump (sump?). He had drawn tap water through a carbon filter. In most cases good old "Chicago" (Lake Michigan) water, thus treated, was great for his young discuss. In other cases he ran RO and treated tap water together in an appropriate mix and routed that to his breeders. While he did that every day, maybe Sunday excepted, those discus grew very quickly.

Also made the acquaintance of Steffen Hellner (author of Killifish: A Complete Pet Owner's Manual) when he joined the old NANFA e-mail list. In addition to killies, he was really getting into temperate zone fishes, including several from North America. In passing, he mentioned that he did  daily 90% water changes, all the time. I greeted him with some news about his book being so appreciated by American killinuts (also mentioned that we were disappointed that it was recently out of print here and he responded that must be why the sudden drop in royalties from N.A.) I did have the temerity to ask if he did 90% changes after being away on a speaking engagement or collecting trip. He was quick to respond that of course not (implying that that would shock them) and that the partial water changes had to be walked up from a more modest level.

Another one of your St Louis confederates, Mike Hellweg (when not using some of your images to put together a live foods book for TFH) wrote a really interesting article on spawning and raising freshwater pipefish. I forget if that was for TFH or for the ALA's publication. Great article. It was noteworthy that he distributed young pipefish, which he had raised, to several experienced aquarists with the admonition that they must be given significant weekly water changes. Mike also lamented that NOT ONE of the people given those pipefishes had had them spawn. He concluded that none of them had been able to keep up with the weekly partial water changes.

I really appreciate your challenge to walk up the frequency of partial water changes and then increase the amount changed. But, given the other responsibilities of most people on Guppylog and the fact that few of us have huge water conditioning vats or pumps to remove the water, 90% is probably unrealistic for the vast majority of us. I did visit a guppy breeder in the north-west Chicago 'burgs who would daily rush home on his lunch break and pull 25% of the water from 80 or so 10-gallon guppy tanks and refill them again. But that is hard to do. And when he reached the venerable age of 40ish, he was backing off of that regimen.

Actually the person with one or two aquariums and maybe two or more of those 5-gallon clear plastic reservoirs for water coolers has a better chance of doing sizable daily water changes than a person with more aquariums. But they may have a zillion other responsibilities (school, work, family, maybe small children, maybe church, coaching and/or other community volunteer efforts, their house might just be in need of maintenance...) And when they are really bitten by the guppy-bug (killie-bug, cichlid-bug, livebearer-bug, etc.) then they have too many aquariums to daily service like that unless they have the good fortune to have a large space near a water supply, drain and consistent room temperature and the opportunity to sit back and plan out all that. To set up a basement fishroom like Jack has (or the 60 x 30 foot fish house Jim-Bob Graham is building) I'd need to buy a new home and have a lot of discretionary cash available. For most of us, myself certainly included, that just isn't going to happen this year or probably any year. :)

But I think your challenge that each of us try and increase the frequency of partial water changes (maybe from every four weeks to every two week or from every two weeks to every week) and then, if weekly or better, increase the percentage of the water changes (maybe from 15% to 25% or  25% to 40% or 40% to 50%) is important! George Maier, aquarium magazine columnist, shop owner, one of the founders of the AKA, used to contend that if we (after quarantining new purchases)  would just do weekly partial water changes our fish would avoid well over 90% of all aquarium diseases.

"Ich? We don't need no stinkin' Ich!"

But each of us will have to figure out how much we can do and how much more we might be able to do in the future. "Different strokes for different folks." Virtually nobody will ever be able to do 90% daily. I doubt Shedd Aquarium does that. So that is a noble goal. Newer aquarists (me too) may just be intimidated by the idea of 90 % daily water changes and want to flee the hobby. ;)

By the way, you did some calculations as to how much the partial weekly water change must be made to stay ahead of nitrate accumulation, in a Killietalk discussion. Would you please share that and how you arrived at that figure? Thanks!

**

"Cleaning the gravel is a little like an earthquake in nature, right?" Charles asked.

I was thinking that pulling the gravel out and washing it was a little like pulling a tree up to examine its roots to see how it is growing. ;)

But as a kid in bc times ("before chlorine" in this case) we used to do something pretty similar to that! I had five goldfish (before the cat nabbed the most expensive and slow swimming ones) and every week would use the old finger thermometer to get about the same temperature in the water run into the "rinsing" side of the kitchen sink. Then the goldfish would be gently slipped in there and the messy bowl would be emptied, washed out and sloshed in the other side.

I had some understanding that the bowl shouldn't be left or touch the bottom of that sink much because soap was a real fish-killer. (Prolly the result of reading some National Geographic article where Amazonian Indigenous people pounded some plants with soapy sap into a creek and pulled all sorts of gasping fish out. Kinda like fishing with hand grenades - where most of the fish sink out of reach).