WATER CHANGES

[pistonville]

My Oscar tank has been set up for about 3 months now. It is 55 gallon tank with small oscars in it. I run a whisper 30-60 water filter.

What I had been doing was changing 25% of the water each week and changing 1 of the 2 filters each week (alternating).

I test my water every week and my results keep coming back the same. My Ammonia and Nitrate are 0, my pH is a little high but that is because of my tap water. It is a problem every fish lover in my city has.

Anyways, my tank seems to be pretty clean as my test results show. I also have 2 algee eaters and 3 corey cat fish in my tank (all very small).


I have not changed my water in 20 days and I just tested it and it is still good. Is it ok if I begin doing water and filter changes once a month???

Help me out, whatcha think???

Thanks
Joffrey aka Pistonville

 

[glolite]

Opinions seem to differ on this. Mostly I think the members here would advise to carry on with weekly water changes but I've heard other fishkeepers say that you shouldn't keep messing with the water if the tests are ok. Probably the larger the tank the more stable it is, a 10g with lots of fry may need 10% daily water changes, whereas a 55g which is understocked and well filtered, like yours, could probably go longer. Perhaps go to fortnightly first and if the tests are ok swap to 3 weekly. You will probably get lots more opinions on here though. I would be interested to hear them too.

 

[Angry_Platy]

The only thing I would worry about is the nasties in the water that can't be tested for....likre when water evaporates things become more concentrated. Fish also release hormones through their skin/scales so may also be a problem if present in high levels.

 

[Fiori]

I thought that were also essential minerals for fish health in water, which are depleted over time; another reason to do a regular water change, even if your stats are reading fine.

 

[CFC]

The main reason for doing water changes other than to remove nitrogen compounds from the water (ammonia/ammonium, nitrite, nitrate) is to replace calcium buffers (KH) which are used up during the nitrification process. As ammonia is converted to nitrite and then nitrate organic acids are released which eat away at the calcium content in the water causing the KH to drop, once the KH level drops too low the pH drops rapidly causing a unstable and highly stressfull enviroment for the fish which in turn leads to disease outbreaks and deaths. The larger the fish the more waste they create and the more organic acids are released into the water meaning that larger and more frequent water changes are needed. I change around 40 to 50% of the water in my largest (200g) tank each week spaced over two days, 30% on the weekend and 10 to 20% midweek as the tank contains several large messy fish, at the other end of the scale i only change the water in my sons heavily planted 30g community tank with no fish over 3" in it at 20% once every two weeks.

For a tank containing any large Cichlids such as Oscars i would recomend changing 40% of the water each week.