major ammonia spike in cycled tank

[Darren Bishop]

Guys...need help. My 20 g tank has been established and cycled for several months now with no issues following cycling. Recently I carried out a full substrate change from gravel to sand...just normal sand untreated and fully washed. All fish were transferred during process into a well cycled tank...once old gravel tank was done and tested fish transferred back.
I continued to test water and for several weeks everything was fine. On one of the water changes I decided to clean the extremely dirty and sandy filter. ..in the normal way...since then my ammonia has gone sky high. I have done several water changes but nothing is working. ..the lowest I get is 0.5 using api liquid. What am I doing wrong?what's caused it? Not lost any fish yet but my two nerites are not happy so obviously something wrong...? help!!!

 

[Aquamandan]

I don't know what caused it but recommend you get 2 or 3 moss balls, they drastically lowered my ammonia spike, took about a week.

Good luck!

 

[Wolfsblood]

Sounds pretty normal for having removed almost all of your beneficial bacteria.

 

[Platiesareawesome]

Guys...need help. My 20 g tank has been established and cycled for several months now with no issues following cycling. Recently I carried out a full substrate change from gravel to sand...just normal sand untreated and fully washed. All fish were transferred during process into a well cycled tank...once old gravel tank was done and tested fish transferred back.
I continued to test water and for several weeks everything was fine. On one of the water changes I decided to clean the extremely dirty and sandy filter. ..in the normal way...since then my ammonia has gone sky high. I have done several water changes but nothing is working. ..the lowest I get is 0.5 using api liquid. What am I doing wrong?what's caused it? Not lost any fish yet but my two nerites are not happy so obviously something wrong...? help!!!

Hello! Welcome to AA! How did you clean the filter? I'm thinking since you got new substrate and cleaned the filter, you got rid of much of your bio filter, as the gravel holds a good deal of the beneficial bacteria, but the filter harbors almost all of the bb. If you happened to rinse the filter with tap water, the chlorine in the water must have killed most of the bb, and you replaced the substrate, which also had much of the bb. So if this was the case, the cycle might be starting over.

 

[Darren Bishop]

Hi thanks for replies. I washed filter in tank water that I had removed as part of water change. I didnt was the filter till a couple of weeks after the substrate change. I had also checked the water regularly and all seemed fine. Tank with new subtrate been set up now for four weeks...filter washed 10 days ago....could this really be my ussue? Will I now go through the whole cycle again?

 

[Platiesareawesome]

Hi thanks for replies. I washed filter in tank water that I had removed as part of water change. I didnt was the filter till a couple of weeks after the substrate change. I had also checked the water regularly and all seemed fine. Tank with new subtrate been set up now for four weeks...filter washed 10 days ago....could this really be my ussue? Will I now go through the whole cycle again?

Well, you did wash the filter in the tank water, which is good, but I'm thinking the substrate the you removed did it. Don't worry it happens. (One time I was fishless cycling my tank, and I used the syringe that I dosed ammonia with to test the water, so the test results made it look like I cycled my tank. Long story short, I had to re-cycle my tank all over again. )

 

[Darren Bishop]

Groaning over now!!thought id done everything by the book....appears I was wrong....I even used majority of the old water ehen I changed to sand!
Oh well....back to the drawing board....thanks to you all