Amount Of Weekly Water Change

[deogan]

I have a 125 gal tank with ten cichlids and four cats. Since cichlids are messy eaters (including oscars) how much should be the amount of weekly water change-20% or 50%? I have two internal filters rated for 2000 lph each. And should I use the gravel vac every week or every two weeks? I am feeding the fish twice a day.

 

[mark7616]

I would only feed them once a day and do a 25% water change once a week and use the vac for that. Also look at getting yourself a large external filter rather than 2 small internals.

 

[darkwolf29a]

In my Oscar tank, I try to do a weekly 20%, at least, water change. Once a month, I try a bit more, like 30 to 50%. Anything up to 50% isn't going to hurt it...I just wouldn't do it every week. Weekly 20 to 30% is good though.

Oscars are notoriously messy, but what you are doing should be fine. I wouldn't worry too much about overfeeding. What you have is just one messy tank. I would gravel vac every time you water change. Being as messy as they are...Oscars can make a mess in a heartbeat.

 

[Amerce]

Got discus and I do a 10% to 20% three times a week, they have a Eheim 2213 external and internal filter to help water quality. I would rather do small weekly changes than a big one if possible. But at least once a month I will try to do 30% with filter sponge squeezes and floss change..

 

[deogan]

Why do we insist on a partial water change? Once the tank is cycled and we have bacteria colonies in the filter and gravel, we can very well go in for a complete water change i.e. 100% weekly. Of course keeping the filter media in water to save the bacteria colonies while we do it. why it is not advisable to do a complete water change or more than 50 % for that matter?

 

[ibbledibble]

Why do we insist on a partial water change? Once the tank is cycled and we have bacteria colonies in the filter and gravel, we can very well go in for a complete water change i.e. 100% weekly. Of course keeping the filter media in water to save the bacteria colonies while we do it. why it is not advisable to do a complete water change or more than 50 % for that matter?

well at least partly because you can leave the fish in the tank if you do a partial. my fish are a pain in the ass to catch and i don't fancy doing it once a week, plus it would be stressful for them. but if i remove 100% i can't really leave them in there can i! i understand a lot of people do 100% changes on betta's in bare bottomed tanks but other than that sounds like more stress and trouble than its worth, both for me and my fish.

 

[TylerFerretLord]

Why do we insist on a partial water change? Once the tank is cycled and we have bacteria colonies in the filter and gravel, we can very well go in for a complete water change i.e. 100% weekly. Of course keeping the filter media in water to save the bacteria colonies while we do it. why it is not advisable to do a complete water change or more than 50 % for that matter?

It's not neccesary and usually a big waste of time.

And for people with larger tanks, filling it up with the proper temperature water would be a pain, unlike the small changes where you don't need to heat the water.

 

[darkwolf29a]

In order to do a 100% water change for my Oscar tank...I'd have to setup a 20 gallon for my fish.

True, more water is better than less, but....it's gonna hurt them to do 20%. Besides, if you have a 100 gallon tank....a 100% water change is going to be a pain to do. But, a 20%...much easier to accomadate. In my 75...it's easy, and I don't have to make my Oscar sulk...he looks so sad when he does that.

 

[Meds081603]

Did I miss something.....what exactly are the other cichlids? I would imagine they are large or they would be oscar food. If they are large then there is no way you should have 14 fish in a 125gallon tank. A single Oscar needs a good 50gallons to himself.

 

[vinylman]

I can understand doing a large water change in a small tank, but conditions in a larger tank would be more stable and wouldn't need a large change, unless something's going wrong. I have a 40-odd gallon and do a 30% change every ten days.