Water Change Regimes

[Mettle]

I was thinking about this last night...

Let's say you have one of those messy fish, like an oscar, a fahaka puffer or piranha. Fish that generally make a mess of things when they eat... If you go in, on a daily basis, after feedings and vac up uneaten bits here and there, and in the end, say, remove 10% or so of the water, doing this every day of the week, is there really a need for a larger water change on one of those days?

Because, by removing 10% daily, you're removing 70% in the course of the week. And the average recommendation for 'weekly maitenance' is much less than this. As well, the small daily water changes may in the end be sufficient to keep the nitrates down as well.

Not to mention that for most fish constant, small changes are preferred to single large ones.

Just an idea that I thought could be discussed. Benefits/draw backs and such.

[328iGuy]

Good question....

Now my next question is why you would even care as you don't have any of these fish listed in you're tanks?  :lol:

[Julie]

My husband and I have a shared maintenance routine on the 90g.
I clean the filters (Fluval 404 and a big Penguin) and he does the w/c.
I don't think the tank has been w/c for at least a month.
Fish are doing fine, there's a big pleco in there also.
We've only been feeding good quality bits to the fish.
So I think it depends on the fish, and how heavily stocked the tank is.  Filtration seems to be the key to maintaining good water quality - while water removes what filtration cannot.

Julie

[mseguin]

Well, changing 10% daily for a week is not quite the same as 70% in a week. I think Marc did the calculations once, but basically, the first day, after you change, u now have 90% old water, 10% new. When u do the water change the next day, you're removing 9% old (hypothetically) "old" water and 1% "new" water. You now have 81% old water, 19% "new" water. Third day, 73% old, 27% "new". Fourth day 66%/34%. Fifth day 60%/40%. Sixth day 54/46. Seventh day 49/51. I think my calculations are reasonably accurate. Obviously, the water doestn actually divide into old and new, but the point is that each time you remove 10% you are not removing as many pollutants.

[Mettle]

Now my next question is why you would even care as you don't have any of these fish listed in you're tanks?  :lol:

I've kept piranha and oscars. (And a green terror, to name another large growing cichlid.)

And I would like to one day set up a tank for a fahaka puffer. So it is pretty relevant.

Besides, for interest's sake.

[328iGuy]

I've kept piranha and oscars. (And a green terror, to name another large growing cichlid.)

And I would like to one day set up a tank for a fahaka puffer. So it is pretty relevant.

Besides, for interest's sake.

I was only kidding...it is an interesting question, I am interested!