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Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 9:30 am
by lindsaydawne81
Hi!

I have a 50 gallon medium medium planted with some large pieces of lava rock. I have had 4 dwarf puffers, 3 otos, and 6 loaches in the tank for about two months. They all have been doing great. Until now.

I've been doing 50% water changes every 7-10 days. Last night I did a water change and forgot to add de-chlorinator :pout: . I woke up at 3am and remembered that I had forgotten to do this and ran downstairs. The puffers were hanging out at the bottom, which was a bad sign as they usually swim quickly to the glass when I walk over to the tank. The loaches were resting on top of the gravel and looked a little pale, they usually hide unless it's feeding time. One of the otos was dead and the other two were quite inactive.

I immediately added the de-chlorinator and within a few minutes everyone was a little more active. This morning, everyone seemed to be acting normal.

BUT... I'm worried about the bacteria. Do you think the chlorine will have killed all the bacteria? It did turn some green algae red. Will my tank need to re-cycle? Should I do water changes more often for the next several weeks, or stick to my normal water changes and watch for ammonia and nitrites?

Thanks!

Lindsay

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 10:49 am
by jus85411
your best bet would be to keep an eye on the levels over the next couple hours to 24 hours. if you see ammonia or nitrite do a water change. it is possible that you killed off some bacteria, but possibly not all of it to warrant a re-cycle, but its possible. you just might have sent your tank into a mini cycle if the bacteria loss was large enough. the bacteria reproduces like wild fire so it could have already caught back up. just test and go for a water change if you see levels. you can also just do a water change as precaution and see if they perk up any more

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 11:16 am
by FADE2BLACK_1973
jus85411 wrote:your best bet would be to keep an eye on the levels over the next couple hours to 24 hours. if you see ammonia or nitrite do a water change. it is possible that you killed off some bacteria, but possibly not all of it to warrant a re-cycle, but its possible. you just might have sent your tank into a mini cycle if the bacteria loss was large enough. the bacteria reproduces like wild fire so it could have already caught back up. just test and go for a water change if you see levels. you can also just do a water change as precaution and see if they perk up any more

+1

You could add a good bacteria in a bottle product to your tank and filters just to help.

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 12:03 pm
by Pufferpunk
50% WC without adding dechlor is fine.

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 2:07 pm
by RTR
It really depends on the organic load in the water when it was added. The "dirtier" the water, the less free chlorine available to damage the bacteria. You do have at least the 50% reduction from tap water levels, and the more aeration during drawing the water and adding it to the tank the greater the reduction in working chlorine. If you faucet has an aerator on it, the blow-off is not trivial. Also, the farther your house is from the processing plant, the lower the residual chlorine. All of those work in your in your favor, so basically +1 to PP's comments if you are lucky.

The appearance of the fish in the wee small hours can be in part normal middle of the night sleep configuration.

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 2:20 pm
by Pufferpunk
Doesn't mean i suggest doing this regularly. ;)

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 3:29 pm
by RTR
LOL! You know me, I always have to hedge things a bit...

I do admit that I have done worse things - I wiped out a two-tank tang breeding setup by using "Excel" rather than "Prime". I did not see it until the next day and it was chloramine rather than just chlorine. Absolutely stupid mistake. The stock bottles are no longer kept side-by-side.

Pobody's nerfect.

Re: Will the chlorine kill all the beneficial bacteria?

Posted: Tue May 03, 2011 7:07 pm
by lindsaydawne81
Thanks everyone so much for your comments! I feel so much better now. I had trouble sleeping last night I was so worried about it. I can guarantee you all I won't make this mistake again anytime soon. I might make other mistakes, but not this one! Thanks again. :twirl: