Why water changes? And whats in our water?

Ok got a question about water and water quality, Like everyone I have been doing water changes for ever and never really bothered to find out why i need to do them, Apart from removing nitrates, Is there another reason for the need to do water changes?

Why do you only have to do water changes every 3 months in salt, and every week in fresh?

And how do these things get taken out of the water in the nature?
Is there a way to replicate this to and make a system that only needs topups from evaporation?

Not being lazy, Just never fully understood it and thought there must be a better way?

Discussion is good

Cheers

[DeagonTheo]

The main reason for water changes is Nitrates,(which inhibits the growth of fry and also is lethal to them in very high doses) also water can crash to a very low ph because of the build up of ammonia.

Having said this, if you have a low density of fish, the need for water changes becomes much less critical, to the stage where you need hardly do them at all.

In the wild, the number of fish per square foot of water is much, much less than in the home environment, also plant life would take up quite a lot of the nitrates.
Then of course you have rain which carries off the old water when there is flooding.

You dont need to do water changes every week if the stocking density is low.

Theo

[ashhhh]

wot theo said :wink:

if there was an easier way I think we would all know about it by now :roll:

[here fishie fishie]

Theo covered the topic well,

Whats in our water?  :? ring the council & hopefully they are forward enough to tell you.  :roll:

The reason we do water changes is that the chemistry of aquarium water is complicated & seeing as an aquarium is an unstable & closed environment. we need to do water changes to keep everything in check.

Frenchy :D

[nemo1981]

i got to keep up the changes on my fry tanks.... :oops:
well at least they're still alive! :D

[quote:2f81b1e79f="ashhhh"]if there was an easier way I think we would all know about it by now :roll:[/quote:2f81b1e79f]

That wasnt really the point, I was wondering if there was a different way, and if not what are the reasons behind it, I relise there isnt really much of an option but to do water changes, But Why? If its only the nitrates that cuase problems then there must be a way to remove them. I guess its probably past the average hobbiests knowledge and price tag to start experimenting with water and ways to remove chemicals.

But if anyone else has a more scientific explaination that would be great.

[DeagonTheo]

I can assure you someone there is no real reason to go anymore scientific than the explanation I have given you. THE main reason is to remove Nitrates.

I gave you one way to remove them, plants. The other ways, you alluded to yourself, are too expensive for the average hobbiest.

There are numerous very good articles out there on water chemistry in the home Aquarium, if you need a highly detailed scientific explanation, let your fingers do the Googling.

But it all boils down to the explanation I gave you.

Theo

[trofius]

along with nitrates there are a lot of other things excreated by the fish, including hormones, and other metabolic by products. obviously the aquarium is a enclosed ecosystem that is void of many of the natuarlly occuring factors including wind, sunlight, currents, strata, and all the tiny players , such as daphnia, and other invertabrates, soil based bacteria and fungi ( not just denitrifying) just to name a few. also a vast photosynthetic, nitrate fixing plant type organisms. Also we add very concentrated, and processed nutrients in the form of food!

But mostly in nature there is the shear volume of water, and it massive movements via current, evaporation and precipitation that continually dilute and recycle everything.

I also think that by doing water changes it keeps the water fresh, just as most of us enjoy a good clensing shower i think even fish would like the freshness of new water...

[Cichlidkeeper]

There are also de - nitrification systems out there http://www.aquaripure.com/index.htm
Check that out, they will post to Aus for $70. OIf you ask your LFS they may help you but I asked almost every gold coast store and only one could confidently help me. In fact they had done testing on a system avail to us and the results were excellent. Still need to do water changes every 3 months to replenish the trace elements in the water but you could run an overstocked tank without the hassles!

[ashhhh]

yes ok sorry grummundi there are different ways, but [i:41406e2887]my point was [/i:41406e2887]the good ol syphon and bucket way for us "average hobbiests" is the cheapest and easiest way.....

On the net I have seen some very old, well established saltwater reef systems that dont even have filters. They just have powerheads and dumpbuckets for watermovement and the denitrification is done all within the tank by the bacteria living in the liverock and substrate.....then all they do is add top up water and the needed trace elements - which are usually fully automated

[wrk21]

grum,
as theo said plants are the way to go.....
i heard of an aquarium in germany that has never had a water change in something like 20 years.... yes 20.
its heavly planted and all they do is look after the plants and plants look after the water.........go figure!!



 ))o

[here fishie fishie]

[quote:838988f51a]its heavly planted and all they do is look after the plants and plants look after the water.........go figure!! [/quote:838988f51a]
It makes sense ah, once upon a time our planet was well planted & keeping everything in check. :roll:

Frenchy :D

[Dyce]

I think to make any system "look after" it self, you'd need an incredibly low fish ammount per tank size.

[DeagonTheo]

I think people are getting a bit carried away nowadays with water changes, it is more critical with fry than older fish.
I saw a bloke on here giving the hobbie away because he couldnt change the water every week.
IT IS NOT THAT CRITICAL.
I have got a round vase that holds roughly 5 litres of water. In it I placed gravel, a floating plant, 6 Platies and water, no pumps or filters of any kind. That was over 3 years ago, all I've ever done is top up the water, there are now 9 Platies in there, they are healthy as. And as you can see breeding.

In a closed environment, fish numbers are determined by the bioload, oxygen etc of the water(I just made that up, but you know what I mean hehe). In other words they will find their own balance
I could go on and on, but the fact remains, if you dont overcrowd too much, water changes arent that critical, and certainly dont give the hobbie away because you cant do a water change every week.

[b:8534ca7380]But also dont forget, they depend on us for their lives, so dont get too lax.[/b:8534ca7380]
Theo