Mistake During Water Change

[Dazmanx]

Hi all,

I'm at the final stage of my fishless cycle on my 110l planted tropical tank. I just completed a 70% water change to get rid of the nitrates before getting some fish in the next few days (ammonia is 0, and nitrites are 0).

Halfway through the WC (about 80l full), I put about 2l of non-dechlorinated tap water in by mistake. I immediately dosed the entire tank with dechlorinator and finished the WC like normal. I'm using Fluval AquaPlus.

I've added 2ppm ammonia and will test the water using my API master test kit in a few hours to know for sure, but does anyone know how likely it is that I've stuffed up my cycle at the final hurdle by killing off the bacteria?

Thanks.

Sent from my Nexus 6P using Tapatalk

 

[fluttermoth]

You should be fine. Although a large water change with chlorinated water could damage bacterial colonies, it would need to be a very large change; well over 50%.
 
The amount of chlorine in a small volume of water like 2l wouldn't create a high enough concentration in your tank to cause any issues.
 
Of course, you should redose ammonia and continue testing for a couple of days, just to be on the safe side, but it's very unlikely you will have any problems

 

[Dazmanx]

You should be fine. Although a large water change with chlorinated water could damage bacterial colonies, it would need to be a very large change; well over 50%.
 
The amount of chlorine in a small volume of water like 2l wouldn't create a high enough concentration in your tank to cause any issues.
 
Of course, you should redose ammonia and continue testing for a couple of days, just to be on the safe side, but it's very unlikely you will have any problems

 
Thanks fluttermoth! I'll retest in a few hours and let you know the readings. I feel better now 

 

[Ch4rlie]

As Fluttermoth mentions, its unlikely you have made any real changes to your cycling process with just 2 litres of water.
 
Bacteria can actually withstand being in chlorine for an amount of time, they are protected by a bio-film all over your tank as well as your filter.
 
I regularly top up my open top tanks with untreated water sometimes, about the same, about 2 litres in each tank. Has no affects as far as I can see, but always better to have a habit to dechlorinate tank water everytime before adding to your tank

 

[Dazmanx]

As Fluttermoth mentions, its unlikely you have made any real changes to your cycling process with just 2 litres of water.
 
Bacteria can actually withstand being in chlorine for an amount of time, they are protected by a bio-film all over your tank as well as your filter.
 
I regularly top up my open top tanks with untreated water sometimes, about the same, about 2 litres in each tank. Has no affects as far as I can see, but always better to have a habit to dechlorinate tank water everytime before adding to your tank

 
Thanks Charlie - your tank is looking great by the way.
 
5 hours later, most of the ammonia has been converted and nitrAte has definitely risen somewhat, so I'm confident the bacteria was unaffected. This was my second WC since starting out - definitely won't make that mistake again!

 

[Akasha72]

I'm sure we've all done something similar
 
I have 5 buckets and each bucket holds 6 litres. I normally change 10 buckets per week (60L). One week I remembered to add dechlorinator to the first 5 buckets then forgot for the 2nd 5 buckets. I panicked too and immediately added enough dechlorinator for the whole tank ... I needn't have bothered as all was fine! 

 

[Munroco]

I never use dechlorinator, I just fill buckets from the tap mixing hot and cold. Maybe I'm lucky with my tapwater but its something I've always done.