Water changes; the real reason?

[k9outfit]

Dumb question, but what's the real reason behind all the frequent water changes? I'll definitely continue doing them as recommended, but I'd really like to know...

Are the Discus so extremely sensitive to nitrates that anything beyond a trace will cause stress, which will result in ailments? Or due to the high temperatures, any food will decay a lot faster than in an ordinary tropical tank, thereby polluting the water quicker? Or are they so sensitive to temperature fluctuations that a larger water change could cause, therefore small, more frequent changes are advised? Or is it to attain maximum growth - rate & size - in the shortest time possible? And, in all honesty, are they really that sensitive???? (I feel like I've accomplished a major feat when I find them still alive in the morning! 8-) )

For instance, it is recommended that water added during water changes on African Cichlids should be within a degree or 2 of the tank water, but definitely not colder. Yet, when doing a 50% water change on my adult tanks, adding water that is 10 degrees F. colder than the tank water, actually induces a spawning frenzy!

[taksan]

What temperature variation ? You should heat your water prior to using it for WC's

[Merrilyn]

Are the Discus so extremely sensitive to nitrates that anything beyond a trace will cause stress, which will result in ailments? Or due to the high temperatures, any food will decay a lot faster than in an ordinary tropical tank, thereby polluting the water quicker?

Both are valid reasons. To understand the need for all the water changes, we need to remember that discus come from some of the cleanest waters in the world, with a very low pH and an almost non existent bacteria count.

Even in the raising tanks in Asia, where the fish are bred in their thousands, the water is constantly changed, sometimes up to 4 times a day. They run the tanks with no filters of any kind, and just an airstone, so there is absolutely no chance of pollutants building up in the tank.

Yes you can keep discus without constant water changes, and just change your water every four weeks or so, and your fish will probably survive. They gradually get used to the rising pollutants, and so manage to survive. However, add a new fish to the tank, who has not been used to the gradual fouling of the water, and you will have a very sick fish indeed, if not a dead fish.

Note that I said your fish would 'survive' not thrive, and certainly not breed. They go into a sort of 'holding pattern' and use all their energy just to survive, while they wait for the better times to come.

I know water changes can be a pain, and I'm sometimes tempted to let it go 'just another day' but then I start to feel guilty, knowing how happy my fish are after a waterchange.

The reason your fish go into a spawning frenzy when you fill your tank with cooler water, is that it simulates the rains in the amazon, when fresh water is flooding into the rivers and creeks, and bringing with it an abundance of food. Natural breeding time for discus :wink:

Keep up with those water changes, your fish will love you for it.

[electric molecular]

That's sage advise Ladyred. Sometimes I feel like letting the water change go another day, but I feel guilty too. I automatically see a lift in my discus when they get fresh water. They seem to quite enjoy it when I clean their tank and give them new water!!

I change my water 2 to 3 times a week (25% changes). I have been doing it a little less often lately since I started working full time and my discus are ok, but I still try to make the effort as I know how the fish love it.

A friend of mine also keeps fish but only changes her water on a monthly basis. When I go over to her house I really notice what a difference there is regarding the size of her fish compared to mine (hers are obviously a lot smaller). I think my fish have grown out well partly due to the frequent water changes, therefore I think it is well worth it.

Claire.