Dechlorinator chemical vs inline filter

[Barry Tetra]

Hello everyone.

I need a tutorial on how to use dechlorinator and need an opinion on what’s better between Chemical vs Inline dechlor.

 

[Colin_T]

A basic dechlorinator contains Sodium Thiosulphate, which neutralises chlorine. If you have chloramine in the water, then Sodium Thiosulphate will break the chlorine ammonia bond and neutralise the chlorine part of it, leaving the ammonia in the water.

Inline dechlorinators are usually things like Carbon and these can remove chlorine but don't always get rid of chloramine. There is no way of telling how full Carbon is and whether or not it can still take chlorine out of the water. Therefore a basic dechlorinator is better for fish keeping because you treat all new water before it's added to a tank with livestock in.

 

[Barry Tetra]

Couple more questions.
Can you dechlorinate water with fish in? I saw lot's of people using dechlor after filling the tank up.

Does RO filter removes chloramine?

 

[Colin_T]

Reverse osmosis filters are meant to remove chlorine and chloramine.

You can add dechlorinator to an aquarium containing fish and then fill the tank with tap water. However, you risk poisoning the fish if there is too much chlorine/ chloramine in the water. The dechlorinator needs time to mix with the water and come into contact with all the chlorine/ chloramine molecules and neutralise them. This can take a while in an aquarium that contains plants, ornaments and filters.

I used to add a double dose of dechlorinator and then fill the tank with tap water from a hose. I did it for years and then one day I filled the tank and all the fish started gasping. I had already put in a double dose of dechlorinator so increased aeration and added another dose. All the fish in the tank where dead within a few minutes. The water company had done work on the pipes in the area and added a heap of chlorine. The chlorine poisoned the fish.

I have seen the same thing happen in other people's tanks, at shops and it happens to people on this forum. They get away with it for a while and one day they lose a tank full of fish.

The safest way is to treat the water in a separate container before adding the water to an aquarium containing livestock.

Fill up a large plastic container or spare aquarium with tap water. Add some dechlorinator. Aerate the water for at least 5 (preferably 30+) minutes. Then use a water pump and hose to pump the dechlorinated water into the tanks. If you fill the container and add dechlorinator and aeration before you start water changes, then it will be well mixed before you start to fill the tank.