Why Water Changes??

[nag]

Hi All:

What's the theory behind huge water changes for Discus?
Why not for other varieties?

TIA,

[Trebs]

There are a number of reasons why discus need better water quality:

Discus tend to carry a number of parasites/diseases when purchased. Less than optimum conditions can see these take hold and the fish will have a hard time recovering.

Discus are kept at higher temps than most tropicals, at higher temps there is less dissolved oxygen and ammo/nitrites are more toxic.

Discus are genetically suited to acidic water conditions. Typically hobbyists kept Discus at higher ph's. At higher ph's ammo/nitrite are more toxic. Also the higher ph is often more conducive for parasites to survive and multiply.

Discus have a relatively large bio-mass when compared to a lot of other tropicals. They create more waste than do tetras or smaller cichlids.

IMO - Most hobbyist overstock their tanks.

That's some of the reasons.

[nag]

Hi Trebs,

These are the general considerations for WCs...
But, is there a scientific reasoning behind large WCs?

A came across a discussion on the other day with one of my friends and he's refering that
"Discus release/secreate hormones which hinder growth...as such large WCs are advocated"

I'd like to know more on this...
Thanks,

[DIY]

Hi Nag,

as far as I know it was Jack Wattley who came up with that theory. Based on his experience Discus became stunted unless they were given lots of water changes. This was just a theory and I don't believe it has been proven or dis-proven.

Whatever the scientific reason is - there is lots of breeders out there that all agree based on experience - lots of water changes are what is required for good growth & healthy discus.

It could just be some trace elements that discus require, and without replenishing these with water changes they don't get them.. I'd be curious to know if anyone has some more scientific answers myself.

HTH

[nag]

Hi there:

...trace elements that discus require...

But, if we're using stored water for WCs wouldn't the trace elements get lost during storage, aeration, temp, et al?
Thanks,