Water parameters and changing schedule

[Blademan]

Hi I would like to ask the advice of the members with a question, I am new to keeping discus and trying to lean as much as possible I understand that the filtration system should break down the ammonia and nitrites but the only way to remove nitrates is by changing water if ammonia is 0, and nitrites 0 but the nitrates are <5-10 PPM as in my case which I think is acceptable, and please correct me if I am wrong, is a water change really required, ie what will it actually achieve.
Just to add i test my water before I change it so I know the parameters, I am currently doing two 30% and one 50% change in my 80 gallon tank per week, I am feeding four to five times a day and my water is consistently in this range, if I lessened my water changes and the parameters stayed consistent, what is the added benefit, I am not intending to lesson my schedule just asking out of curiosity
Thanks

[Lotticd]

Good questions i would like to see our resident experts response.....

[John_Nicholson]

This has been beat to death more times than I can count. There is a lot more to water than just the things that you mentions. Do a search on DOC's and you will find lots of info on this site about why you need to change water if you want to grow out large, healthy fish.

-john

[afriend]

Hi I would like to ask the advice of the members with a question, I am new to keeping discus and trying to lean as much as possible I understand that the filtration system should break down the ammonia and nitrites but the only way to remove nitrates is by changing water if ammonia is 0, and nitrites 0 but the nitrates are <5-10 PPM as in my case which I think is acceptable, and please correct me if I am wrong, is a water change really required, ie what will it actually achieve.
Just to add i test my water before I change it so I know the parameters, I am currently doing two 30% and one 50% change in my 80 gallon tank per week, I am feeding four to five times a day and my water is consistently in this range, if I lessened my water changes and the parameters stayed consistent, what is the added benefit, I am not intending to lesson my schedule just asking out of curiosity
Thanks


Blademan,

Assuming that the tank has a well established biological filter, the main reason for making large water changes is to remove dissolved organic compounds. DOCs come from two sources: uneaten food and feces. The DOCs are not harmful to the fish, however there are bacteria in every tank that feed on them and this results in other compounds that are toxic. This process is common in nature as evident by the foul smell of a dead animal or decaying vegetation. Water containing large amounts of DOCs, while appearing crystal clear, can contain more than sufficient contaminants to stress discus.

The thing about discus is that they are easily stressed, not only by the contaminants formed by DOCs, but by changes in temperature, Ph, overcrowding, and even the pecking order established in the tank. When a fish becomes stressed, it usually becomes lethargic, stops eating, and this makes the situation worse because it becomes more susceptible to pathogens (bacteria, virus, and parasites).

The immune system of the discus also plays a part in this equation. For thousands of years the immune system of the discus has evolved in water with a low Ph. Water with low Ph has not only far fewer pathogens, but also a different class of pathogens as found in water with much higher Ph. Thus when the discus becomes stressed in water that has not only a higher concentration, but also pathogens that the immune system has difficulty in overcoming, the result is usually not good for the fish.

Just because the water appears crystal clear, this is not sufficient for healthy conditions.

Paul

[John_Nicholson]

Some of what Paul said I agree with and some of it not so much. I agree with the DOC part but not the low Ph. Some of the Amazon has low Ph and some of it does not. Discus evolved in both parts. They are not really that easily stressed. In winter my wg's often drop the temp in my tanks from 82 to about 70. Since the fish are truelt healthy they handle it wihtout any issues.

-john

[bluelagoon]

Changing water also replenishes elements needed for growth.

[Blademan]

Actually increased my water changing to 80% three times a week, the fish seem better for it