Large water changes

[Zander_The_RBP]

As long as water changes are consistent you have nothing to worry about. Infrequent water changes can lead to "old tank syndrome" the gradual decline in the pH of an aqaurium over time. Consistent water changes Replenishes the buffering capacity of the water and prevents the drop. You could do 100% water changes weekly but doing 75% changes monthly is a bad idea.

It is the suden pH swing that harms fish. Not the new water.

 

[Industrial]

Just about all my tanks get 50% water changes weekly. I never go over though. As long as you keep up on tank maintenance changing half the water doesn't really alter water chemistry enough to have any visible effects on the fish. If I go any larger, it is usually unnecessary and sometimes my fish appear stressed. If I go any longer (2-3 weeks) between water changes and change half the water, normally my fish color up nicely and sometimes even begin to spawn. I only do that though, when I want the the fish to spawn. If it happens on a regular basis it causes a few fatalities.

If I do too large of water changes at once, or too often my plants will oftentimes suffer and many of my systems get a big messed up. I think larger water changes are excessive and never really accomplish much more than a 50% water change. And sometimes at work, the fish become stressed and occasionally tanks will crash when I change too much water.

Old tank syndrome is something that no dedicated fish keeper should ever cause. I had it once, my pH dropped to 7.4 from 7.8 because I stopped gravel vacuuming a planted tank for a couple of months and only did 20% water changes biweekly. Preventing old tank syndrome does not require 100% water changes or daily 20% water changes. In almost all applications 50% weekly gets the job done.

 

[clgkag]

I usually do between 50-60% every change no problems. If I am starting a new tank, I just run the new filter for a couple weeks on an established tank. Then move the filter and start the tank.

 

[Chizzle]

I change 30-40% every 3 days. You should see how much crap comes out of my gravel during each change!

 

[SeaN_]

Sorry, I'm 1 of the 3 with ill effect and it was due to me not reading fully, i do 50+ multiple times a week with no ill effects

 

[SimonL]

Wait for it, tap water still has a chemical make up just like tank water! Sure they may be different than the previous tank but that's why you can acclimate the fish using a drip method.

Tap water has a chemical make up "just like" "tank water"?1? Please describe this in further detail. You are saying that all tanks have the same ph/hardness/dissolved oxygen/C02/nitrates/phosphates/metal content as the water that comes out of the tap? Whose tap water? Yours? Mine?

As far as tank and source water goes, as long as one is doing weekly waterchanges the ph and hardness should not vary greatly unless one is using something to alter the water

Unless you're one of those responsible fish keepers who likes to emulate your fishes' natural low ph, soft water habitat (like the majority of aquarium fish).

If using tap water is so bad, why do we use it to do waterchanges?

Who said it was bad? We're talking about chem changes.

You have also stated and argued that doing large water changes is a shock to your fish.

I didn't say large water changes, I said changing 99% of your water could stress/shock/kill your fish. Emphasis on could. And it depends on what your fish are used to.

You see there are already several ppl who have set up new tanks using established filter media and more than likely tap water, with no I'll affects

I had an old boss who told me a story of drinking a quart of whiskey with his buddies and driving down the highway hanging out the windows. With no seatbelt. By your logic, because he didn't perish, this is apparently a good idea. And you are reaching for your conclusion, I don't see one response of "I like to do 99% WCs"

 

[Otolith]

I do 80 or 90 percent on my FW tanks every weekend usually. Fish I have now flourish with it. I've killed a few senstive cats and bala sharks tho doing it that way.

 

[Bderick67]

Not sure what the debate is about. Does seem there is more to it then what the "poll" shows. As far as 90 to 100% water changes, I wouldn't recommend them, as it can increase the chance of shock. This does not mean there will be shock, just that it increases the chance. I think the most important factor is whether or not the fish is healthy to start with. Hitting an ill stressed fish with a 100% water change would likely lead to it's demise. While a perfectly health fish will likely show no ill effects from the W/C.

As for me. All my fish/tanks receive large W/Cs one a week some twice a week. When I set up, upgrade, or transfer to another tank. I move fish, filters and enough old water to the new tank that when I fill the tank up with new water it is just as if the fish are experiencing a 50% W/C.

 

[SimonL]

The debate began in another thread about moving tanks. I suggested that the OP should move some of his existing water with the fish, as he lives around the corner. creepyoldguy disagrees, saying it's fine to just set the tank up with 100% new water and move the fish in.

http://www.monsterfishkeepers.com/forums/showthread.php?t=402551

 

[creepyoldguy]

Simon the basic makeup of water changes very little from source to tank and if ph and hardness and nitrates etc drop or rise dramatically it's either because your altering it or not changing water. As far as emulating your fishes natural habitat, I know immune adding a bunch of chemicals to Alter it. My fish including my rays all live in waters different than their natural habitat. If you don't think there are many ppl who keep discus rays or sa cichlids in high ph or harder water, you should spend some time asking around

As far large waterchanges go, I never said I liked doing 99% water changes but said my fish could handle it as well as many other ppls fish who change their water. What about breeders who do large cold water changes to imitate the rainy season to get fish to spawn. I guess that's another fish killer