Filtered Water

[paolo]

Is it ok to use filtered water to top up my tank?
We use a water softener, but have a plumbed in water filter that is fed by mains (hard) water. The filter also gets rid of the smell of chlorine, so I assume it is chlorine free too.

 

[saz326]

I wouldn't.

People often put on this site that demineralised water or filtered water is okay to top up tanks with - but that simply strips out salts and minerals that your fish need to live healthy lives.

It is safe to use demineralised water or filtered water AS LONG AS YOU REPLACE necessary nutrients like salts and minerals.

A water filter will remove chlorine and some of the heavy salts and scales which is fine for the fish - but things like snails and shrimp need carbonates and salts to make their shells..... fish need certain salts in the water to promote breading etc..

If you want to use filtered water, I would suggest you dont use it all the time, or you also add a water treatment/conditioner such as this: http/www.eshalabs.com/optima.htm

This will replace the salts lost in the water filter, and help to recreate natural water values.

Id stick to tap water unless you know that there is a problem with it.

x

...edited:

Just re-read the original post..

Your tap water softner may add salts to the water, simply preventing the effect of carbonates (e.g. limescale)

contact the supplier to see what gets added to the water, and then let us know so we can help. xx

 

[raptorrex]

Is it ok to use filtered water to top up my tank?
We use a water softener, but have a plumbed in water filter that is fed by mains (hard) water. The filter also gets rid of the smell of chlorine, so I assume it is chlorine free too.

I'm inclined to agree with saz326. whilst i am far from convinced, the arguments are good enough to make it not worth the risk.

Many water filters use carbon as a major part of the process. this is said to leach, or probably leach, some if its captured containments, after a short while. many use silver as an anti bacterial agent. whilst there is no firm evedence that this form of silver is a problem for fish, until l it is confirmed as safe, we should be wary of its use. demineralisation may also be a problem, but how much of a problem? to me not much! though i have no experience with chemical water softeners, in fish keeping, i would think, they may be a problem. as stated it is often salt that is used!

 

[paolo]

What about rainwater?
I have a large rain butt full of it in my garden, that I could use.

 

[andywg]

What about rainwater?
I have a large rain butt full of it in my garden, that I could use.

Rain water is fine to use but it will be somewhat soft and acidic. Many recommend running it through some carbon to help ensure any potential pollutants are removed.

There are a couple of people on here who use rain water for softwater tanks.

 

[OldMan47]

For top off, the more pure the water the better. The water that has evaporated from your tank has left behind all of the chemicals that it contained. Replacing that with pure water is a great idea. On the other hand, doing a water change with pure water does mean reducing the mineral content of your tank water. Depending on what fish you keep and what the mineral content of your tank, using pure water such as DI or distilled can adversely affect the fish by removing too much of the minerals in your tank water.