Ammonia/nitrate spike

[Dirtyd301]

Hi! My tank has been established for about 5 months. Always have good parameters and do a weekly gravel vacuum and 20% water change.
The past couple weeks my nitrates have been slightly high. Yesterday I cleaned my filter because it hadn’t been cleaned in a long time. I was afraid to mess with good bacteria but thought maybe a dirty filter was causing the nitrates to increase. I checked my water today and now the ammonia is going up too?! I used tank water in a bucket to clean the filter. Any other thoughts or advice? I will do a large water change tomorrow to bring it down.

 

[ColdKoi]

What type of filter do you have and what exactly did you do when cleaning it?

Nitrates are the end result of a typical nitrogen cycle. It’s elevated numbers only indicate that the beneficial bacteria are doing their job and the bio load in the tank has increased (added fish, feeding more or different food, or decreased water changes). Nitrates are only lowered/removed with water changes in most typical setups

After washing the filter, you removed some beneficial bacteria, thus the rise in ammonia. Unless you got really carried away cleaning the filter and removed a substantial amount of bacteria, it’ll be back to normal in no time

 

[Dirtyd301]

So having some nitrates is ok? It was staying around 5. I have a 20 gallon Tetra tank with a HOB filter. To clean it I took water from the tank and put it in a bucket. Then I put the filter in the bucket. Squeezed out the spongy thing and wiped the filter clean with a towel. Then put it back. How often should I be cleaning the filter? It has been months

 

[Aiken Drum]

Typically you want to keep nitrate below 40ppm.

 

[ColdKoi]

Nitrates are ok in lower concentrations, even high concentrations for short periods of time. Like mentioned above, 40ppm is generally considered the safe limit

Which type of hob filter is it and what type of media is in there?

Filter cleaning intervals really depend on the particular setup and your own preferences. Generally you never want to do a full filter clean all at once as you risk losing too much beneficial bacteria

I have a fairly high bio load in my 29g that has an aquaclear 70 hob. I do water changes usually every 1-2 weeks, during that time I usually pull one piece of media out of the filter (one of the sponges or bio media bags) and rinse them gently in the used tank water. In the ~6 months it’s been set up, I’ve only recently cleaned out the filter housing itself for the first time (no media cleaning at that time). I have yet to see any ammonia spikes after maintaining my filter this way