Water change can you do this?

[Hifishman]

Hi guys any of you do a water change like this? You drop your tank water down say 10% then treat the tank with de chlorinater liquid add enough to treat 10% of water your adding then add a hose from tap and fill tank up slow? I no prime say treat full volume but how meny guys with ponds would treat a pond full volume with de chlorinater liquid be adding so much liquid so why different for a tank

 

[abw0004]

You need to add the full amount. You really have to try to kill a fish with Prime, but you don't have to try hard to kill a fish with untreated water.

 

[J.Mcpeak]

Easiest to treat the bucket. Depends on the refill method.
Treat the entire tank if you must do it that way.

What's the volume of the change?
20-30litres I'd do in a bucket.

 

[Hifishman]

Hi ok you would need to treat full volume with a de chlorinater liquid then seems alot of liquid to add some aquatics say your only adding 10% of chlorine so why treat full tank you only do that when you first fill it from new i don't no what to do? Some say full amount and some say treat just what you add I thought would ask know here to see what you guys do when water changeing

 

[J.Mcpeak]

If you have no Chloramines in your tap water (test for ammonia)
You don't even need to treat the water, just aerate for 24 hours.

It's easier to treat the bucket! (Or more cost effective)

Ultimately the choice is yours.


Edit.
The problem is, a small amount of chlorine will quickly reset your tank. Then you have a major problem.
Chlorine is intended to kill bacteria. It just does that and very well. It is indiscriminate, that is it doesn't care if you consider that bacteria to be beneficial to your tank or not. It will just kill it.

Then you'll start losing fish. (Possibly)

Sorry that's blunt but that's the bare faced facts.
You may be ok, but personally I wouldn't risk it.

 

[Hifishman]

Would you say treating the tank for just the 10% your adding the de chlorinater is weaker when added to tank that's why you treat full volume

 

[J.Mcpeak]

Honestly, I looked at this problem over a decade ago. My conclusion was, it is safer to add water already prepared for the tank, to the tank. (See above, dose a bucket)
Main reason being I love my fish, the health of animals in my care comes first, the ease of the process is always second to that.

I have never added fresh (untreated) tap water to an overdosed tank and if I had to for whatever reason, I would certainly ensure absolutely no way in the world, could that water affect my fish or the tanks biological situation. There is only one way to ensure that, dose the tank by volume complete.

Now I'm even against this, and I use a water mix prepared by me. Just because in my area things like heavy rain can affect nitrate in tap water. Which is still within the government guidelines but way out of spec for me.

 

[nirbhao]

Are you familiar with brownian motion? The goal with treating the whole volume to to make sure any chlorine or chloramine meets dechlorinator before it meets nitrifying bacteria.

 

[J.Mcpeak]

I wasn't expecting that!
Add in fluid dynamics and thermodynamics, maybe a dose of hydrodynamics for good measure.
Then test the results. Let me know what you find out.

Probably easier to dose a bucket or the tank!