Water Changes

[Kirky1986]

Evening all,

When i do water changes on my big 400l tank i refil with a hose connected to the indoor tap to get the temp right.

Now my question is with me refilling it this way i cant add water conditoner beforehand like i do on my small tank so do i add enough conditoner to cover the water being replaced or the full 400l??

Ta!

 

[eaglesaquarium]

Add for the full 400L.

 

[Madness13]

Wouldn't you just need to dechlorinate the new water? The old water has already been dechlorinated.

 

[eaglesaquarium]

When adding water straight from the tap, you add enough for the full volume of water, because of many factors including: dilution, and other substances in the tank, which will cause the dechlorinator to be less effective against the chlorine and chloramines.

 

[BerryAttack]

add for 400L.. eaglesaquarium has the right info

 

[Madness13]

Oh that makes sense! Does the same logic apply to a smaller tank?

 

[eaglesaquarium]

Only if you are adding water directly from the tap (via a hose, for example).  If you are filling buckets, feel free to add the dechlorinator to the bucket only for the volume of the bucket.

 

[Madness13]

Thanks Eagle that's awesome.

 

[Kirky1986]

Yeah i thought as much! Will continue adding for the full volume of the tank!

Thanks for the advice!

 

[KirkyArcher]

I just add for the amount of water I refill with no issues , (the use of Seachem Prime water conditioner seems to be the reason behind this dose for tank idea as far as I can understand) But would like to ask the question If I may to those who recommend dosing for the full tank volume, Say for instance Kirky1986 (good name

) only changed for what ever reason 5-10% or even less due for example after doing some filter maintenance and had to top up the tank to refill the filter/filters of his 400 litre water volume would you still recommend dosing for the full tank volume if he used the hose pipe refill method?
 
*There has been at least one report of fish deaths that has been linked to overdosing using certain dechlorinators in the manor suggested above when he tried it for the 1st time (dose for tank volume) that I know of 

 

[eaglesaquarium]

If I am only changing 5-10%, I don't treat the water at all.

 

[fluttermoth]

If I am only changing 5-10%, I don't treat the water at all.

Nor do I; don't bother for top ups either.

Obviously, we don't want to be exposing fish to 100% raw tap water, but the level of chlorine/chloramine in our domestic supplies is not strong enough to do any harm if you're only talking a small % of the tank's volume.

I've actually done 50% changes with chlorinated water without causing any issues.

 

[KirkyArcher]

So is there a specific/recommended  "minimum percentage" of water change volume that suddenly necessitates the leap from not dosing any water conditioner (so far 5-10%) to dosing for 100% of the aquarium water volume and why?  Sorry to be a pain I just can't get my head around this at all

 

[fluttermoth]

Generally speaking (obviously different places have differing levels of chlorine/chloramine in the water supply) for water changes of 50% or less you wouldn't need a dechlorinator.

Anything over 50% would lead to too much chlorine/chloramine being present and could affect the fish, or the filter bacteria.

 

[KirkyArcher]

Fair enough but it all sounds too vague to me, I'll continue to dose the correct amount of dechlorinator for my 35% of water (66 litres)