Arowana Water Change URGENT

**fishery** · 02-11-2013, 08:24 AM

I need to give a 50% water change for my 63 Gallon tank.
Would it be okay if I remove 50% of the water from the tank and then add the Anti-Chlorine to water in the tank and then fill water using a hose to the tank.
The water from the tap contains chlorine for sure and hence I will be adding the Anti- Chlor to my tank prior to adding the chlorinated water.

I have tried this approach with my molly tank and it works fine, but the molly tank has a cloth/sponge filter that is external, but my Aro tank has a Underwater Gravel Filter, so will the chlorinated water from my tap kill the beneficial bacteria in my UG filter instantly, or will the Anti chlor in the tank dechlorinate the water on the fly before that happens.

Any ideas would be great.

**rodm81** · 02-11-2013, 08:37 AM

I done it that way plenty of times and had no issues. You should be good doing it that way.

**fishery** · 02-11-2013, 09:00 AM

Okay thanks, I ll give it a go next Sunday. Fingers Crossed.

**Lady Hobbs** · 02-11-2013, 09:54 AM

I hope the water from the hose is not a lot difference in temp than that in the tank? Too big of a change in temp will shock the fish.

**fishery** · 02-11-2013, 10:23 AM

I mostly change the water at night so the temperature from the overhead tank and my aquarium should be mostly same maybe + or - 1 degree Cel.

**Crispy** · 02-12-2013, 01:39 PM

I like to dechlorinate before the water goes into the tank. But others do it differently and it seems to be OK aswell.

**KevinVA** · 02-12-2013, 02:53 PM

I do it differently for 4 different tanks. My 75gal gets prime in the tank and then I add the water. My 10gals get bucket changes and the prime is added to the bucket water before adding to the tanks. Same result either way. It's just easier for me to use buckets on the smaller tanks. Well... not easier on me, but easier on my 10gal tanks.

**Sandz** · 02-12-2013, 04:34 PM

The attomic reaction that takes place in the detoxification of ammonia is almost instantanious. To remove water, add dechlor (enough to treat the entire tank) and then to fill with same PH and same Temp water will be fine. Also, ammonia and chlorine will kill BB but not the fish right away. It takes a fair amnt of time to get that done.