How stressful -are- water changes?

[Taratron]

I recall an old friend of mine who had perhaps one of the most neglected fish tanks I've ever seen. A 20 gallon tank with many guppies and 6 or so bronze cories. The tank was fed heavily every day, and water changes perhaps once a month. Her cories, fed Tetra and Hikari, spawned nearly every day for weeks in the winter months.

My bronze cories, at the time, were also in a 20 gallon tank, with a sole male betta, and were fed NLS pellets, and water changes three times a week, up to 50% each time. They spawned only once, and that was after many attempts.

I know that plecos are high waste producers, but my current water change schedule, the same as above, doesn't seem to help nor hinder them. When I was off work, I did 50% daily, and could see my albino bristlenose growing. But now at three, sometimes four times a week, I see little activity no matter how often I change the water, or if I skip a day to see if that brings them out more.

Doing more water changes, is that hurting my attempts to breed my bristlenose and bronze cories? Is the process stressful overall?

[Barbie]

These fish tend to spawn when the water conditions CHANGE. You're keeping them rock solid stable with the frequent water changes you're doing, so yes, in some ways, you're hindering your attempts to spawn them. You'll grow the fish faster and be able to feed them more to condition them safely, but as far as stimulating them to spawn, you'll need to stop changing as often to get them going, IMO.

If you tell anyone I EVER told you to change less water, I'll deny it ;).

Barbie

[Taratron]

Of course, of course, Barbie.

So would you recommend just one change a week? Or perhaps let the fish sit in "soiled" water for nearly two weeks, and then do a huge change with cooler water?

[Shane]

So would you recommend just one change a week? Or perhaps let the fish sit in "soiled" water for nearly two weeks, and then do a huge change with cooler water?

One good water change per week is enough for an average stocked tank with good filtration. Some sp. are more likely to spawn if the conditions are kept stable for some time and then changed. Try two weeks without a water change and then a 25-30 percent change with RO water. That should set them off.
-Shane

[Taratron]

A question on water: is RO the same as distilled? I'm having problems finding RO that isn't flavored with something, or has additives.

[MatsP]

RO is a different process than distilling, but the net-result is the same, at least if all is done right. RO water is without any minerals, thus very soft and with a pH of 7.0.

--
Mats

[B-2]

I do about a 50% water change once every 1 to 2 months in my 50 gallon tank, and even less in my goldfish barrel. All my fish seem just fine with this. I have my tanks in our basement where there is only cold water, so whenever I do water changes, it takes the whole day. Filling the tank up takes the longest. I can't put too much cold water in at a time, so I leave the hose on at a trickle, wait an hour or two, and then see if the tank is full yet. I usually clean the filters during water changes. I do water changes more often in the warmer months since it dosen't matter if I get wet then. I also have more time in the summer to change the water.

[Marc van Arc]

It strikes me that:
- most people do a water change every week or even more often. I only did that when I had an African Lake tank.
Imo (and experience) South American (cat-)fish aren't very fond of it.
- people do a water change of 50%. I have learned to change 33% (or even 25%), because there is an apparent risk of turning over the water quality when doing a 50% change.
I have to add that we have rather good water coming from the tap; perhaps a lot of you aren't so lucky.

[MatsP]

This is probably one of those issues where you can be religious...

I do big water changes on some of my tanks - because I'm lazy enough not to want to do twice a week - this is a tank that has a fair number of bristlenose babies of varying size from newborn to sale-able.

On my bigger tanks, it's more like 25-30% per week.

I can't say my catfish seems to be unhappy with this regime, they behave just he same before and after - when I was moving house and went a couple of weeks between two water changes I could clearly see that the fish weren't particularly happy with the situation.

But an important factor is of course how heavily stocked the tank is... If you have a large tank with few fish, then doing big water changes is probably a waste of time. Unfortunately, I'm too greedy to be able to just keep a few fish in each tank [or I've got too few/small tanks... ]

It's of course important that the water added when changing the water is relatively close to the water in the tank in chemistry (pH, hardness etc) so that the fish aren't shocked.

When I was young, I'd clean the tank a few times a year - and not change water at all. I'm pretty convinced my fish are happier now...

--
Mats

[Shane]

There was an article recently in one of the US aquarium magazines (I can find the ref if anyone wants it) about a seminar of vets and public aquarium professionals. They all agreed that the very fisrt, and best, treatment for any fish not looking its best was a big water change. Cures more maladies than any medicine.
-Shane