Is water change really neccessary for fresh water tanks?

[kidearth]

Hi everyone, I have a community tank and so far i only top up water. The tank houses golden algae eater, shrimps (sakura, crs..) and guppies.

I only change 10-20% of water every week when there is algae outbreak. Other than that, I just do top ups. So far all inhabitants are ok and active.

Any advice?

[VSGenesis]

Do what works for you.

1) Some people will do water change every 3 days. 15% to 25%
2) Some people will do water change every week. 15% to even 50%
3) Some people will do water change monthly.

These are the common ones I heard. Usually water change is conducted together when topping up is needed.

4) Some people with amazing DIY setup with filtration, will only do water change of up to 25-40% every 3 months. (220g tank, diy filtration system with god knows what, too noob to understand the guy.
5) Some people will not even do water change even when their fish are floating on the surface upside down.

No 4 seen but rarely heard of..by me at least.
No 5 don't hear it. Rarely. I hate seeing a half skeleton fish in an lfs and they don't bother cleaning it up.

Anyway, to find out more about water change, just search it in AQ. This topic was last seen not long ago.

[Navanod]

The common problems with simply topping up instead of changing water:

1. Nitrate build up. Can be avoided by growing alot of plants and then harvesting these plants often.
2. GH build up. Can be avoided by investing in RO water for the top up.
3. TDS will build up. Plants and certain type of filters can remove some of the TDS but in the long run, I believe there'll be issues with nutrient imbalances.
4. Exhaustion of minerals and imbalance of redox potential. Can be avoided by adding minerals during topup. But spent minerals (yes, minerals take part in redox reactions and can be expended, having received or donated electrons) will accumulate and GH will build up.

Also, water changes simulates rainfall, so some species may exhibit abnormal behavior if there's no rain for a prolonged period of time. Eg. Some people claims to see more shrimps molting after a waterchange.

[SeVenZ]

i guess the same analogy can be used for humans? if the air we breathe kept cycling in a room without the exchange of fresh air every now and then, how would you feel?

[kidearth]

i guess the same analogy can be used for humans? if the air we breathe kept cycling in a room without the exchange of fresh air every now and then, how would you feel?

hi sevenz, noted. guess i should not be so lazy. will practice the water change for my tank

[tetrakid]

If the ecological environment in the tank is functioning in a continuosly balanced state, there is no need to disrupt it. Disrupting a balanced environment by big water changes will only stress the fish and other aquatic life in the tank. On the other hand, small water changes at good intervals will help to create a buffer to dilute any toxic agents present.

i guess the same analogy can be used for humans? if the air we breathe kept cycling in a room without the exchange of fresh air every now and then, how would you feel?

[sheristopher]

Seem like regular small water change is the way to go

[Blue Whale]

kidearth,

Read this,
http://www.americanaquariumproducts...._cleaning.html

When doing water change, watch out for your baby GBRs. The mother is doing fine with the kids.

[bernie]

Interesting articles from this site called maths-only aquarium.
They use a maths formula to prove that weekly WC of 25% is best.
The site also have a spreadsheet to help you find out how your aquariurn is stock and it's potential risk.

http://sites.google.com/site/moashow...nges-necessary