Dechlorinator

[markandhisfish]

when doing water changes and adding the dechlorinator can you use too much and ultimately harm your fish?

 

[peter22UK]

if we are talking way too much....then yes i guess so

personally i dont use the stuff tho

 

[fishlover500]

I think on my bottle it says it doesn't matter if you use to much, although maybe it means to a certain extent as in, don't dump the whole bottle in.

 

[kim03333]

i think i often use more than is instructed on the bottle. the reason being that you are meant to use one small capful for 45 litres. these cap measures really are small so when i'm doing my 25% water change, i'm replacing about 25 - 30 litres. therefore i have to measure half a small capful. and to make matters worse, the bucket i am using (until i can find a more suitable larger one) can't hold all at once so i have split this into 3 10 litre additions. so now i'm down to a quarter of a small capful each time! this is a minute amount and it's really hard to measure as theres no measurement guides on the cap. never mind it's all good fun!

in answer to the question, i've yet to see any harmful effects on my fish

 

[Bignose]

Long, long time ago, there was a forum member who sent in a letter to TetraTec asking this very question. The reply from them was that their testing has shown that they can overdose by more than 50 times and the fish show no ill effects. The only harm seems to be to your wallet. I haven't used a tool to measure the "correct" amount since I first got started. Since then I always poor out what seems like the right amount, being a little liberal and no doubt putting in more than a "correct" measurement would be. I think that there is no need to worry about using too much.

 

[markandhisfish]

thats good to know as i change my water using a bucket and jug. so i err on the side of caution and put about half a capfull in each bucket as i thought more would be better than not enough

 

[minxfishy]

I double dose my tanks as I re-fill via python, I just chuck one amount in before filling and the other after filling.

Im pretty sure it would take an awful lot to harm the fish, so nothing to worry about really.

 

[mike os]

from where I stand ANY dechlor is too much LOL

 

[waterdrop]

Most of what I have seen discussed on TFF has upheld comments by Tolak and Bignose and others that extra dechlor is harmless to fish and that in fact a bit of overdosing can be good for the occasional situations where the water authority has put in levels of chlorine or chloramine that are higher than usual.

However, the assumptions here are for both a mature biofilter and generally mature tanks with fish.

In a discussion with Tim Hovanec, he indicated that there is some evidence that excess amounts of dechlor may inhibit optimal growth of the beneficial chemolithoautotrophic bacteria we are trying to grow during a cycling situation. Other than this comment by him I know of no published evidence of this but I still take it to mean that it could be prudent behaviour during a fishless cycle to only let your rough capful type measures go over by a little bit, rather than pouring in larger random amounts.

~~waterdrop~~