Crashed Cycled Tank

[Denise T]

I believe that I somehow crashed my cycle.  I just went thru 4 or 5 days of high ammonia levels, and I did 50 percent water changes everyday and used fritz complete (this is in my 75 gallon south american cichlid tank), and this morning when i tested the water, my ammonia levels have gone down (not 100%), but not nitrites are high - which doesnt surprise me with having high ammonia for days.  Three questions. 

1.  Does this sound like the tank crashed its cycle and has started again?

2.  I am doing 50% water changes every 24 hours (in the evening), I did just add more fritz complete this morning because of the high nitrites.  Can I still wait to do a water change this evening?  Will by adding the fritz complete get the fish thru the day?  I have 2 bubble stones in the tank to help my fish with oxygen

3.  When you clean your filter media, should i leave one of the sponges dirty?  I usually clean all the sponges in tank water.  Not sure if this could cause the cycle to crash.

Thank you for your help

[Root]

Hello! How old is this tank and how often do you clean the sponges?

[JettsPapa]

1. It sounds like it has, assuming it was fully cycled to start with.
2. Do 50% water changes whenever needed to keep ammonia and nitrites low, even if that means more than one per day (their toxicity depends on pH, but keeping the combined values below 1.0 ppm is a good rule of thumb).  I wouldn't add any other chemicals or miracle bottles of bacteria (other than dechlorinator, of course).  They aren't a substitute for water changes.
3. Assuming your tank is fully cycled, rinsing both sponges shouldn't be a problem, but it might be best to only rinse one at a time until you get things under control.  I assume you're rinsing them in water you've taken out of the tank?  A quick rinse under a faucet isn't generally a problem in well seasoned established tanks, but you aren't there.

[Denise T]

 

Hello! How old is this tank and how often do you clean the sponges?

 

This tank is a few months old.  I did a fishless cycle before adding fish.  I tested the tank everyday to make sure we were good.  My filter is a secheam tidal 110 (hang on the back filter), it has a blue pop button for when the filter needs to be changes.  It usually requires changes once a week

 

[JettsPapa]

On 9/5/2023 at 2:37 PM, Denise T said:

. . . My filter is a secheam tidal 110 (hang on the back filter), it has a blue pop button for when the filter needs to be changes.  It usually requires changes once a week

 

Just to be clear, are you changing the filter media, or rinsing it and putting it back?

[Pepere]

How many and what sized fish are you stocking?

There are oh so many variables with fishless cycling.  You may well have an established cycle but it is possible to exceed the amount of fish that cycled filter can handle and the filter needs time to catch up…

[AndEEss]

On 9/5/2023 at 1:37 PM, Denise T said:

 

Hello! How old is this tank and how often do you clean the sponges?

 

This tank is a few months old.  I did a fishless cycle before adding fish.  I tested the tank everyday to make sure we were good.  My filter is a secheam tidal 110 (hang on the back filter), it has a blue pop button for when the filter needs to be changes.  It usually requires changes once a week

 

What are you doing to "clean" the sponges? What are these "changes" you are doing"?

The only maintenance you should need to do with those filters is taking the sponge out, slapping it against a tree two or three times, and put back in the filter.

If you're actively CLEANING your filter sponges, yeah, you're going to crash your cycle.

Edited September 6 by AndEEss

[Denise T]

I don’t put new sponges in.  I put back all the sponges. I rinsed in the tank water back into my tank.    I also have purigen and phosguard in my filter. The only think I put In new, is the filter floss.  
I have a 75 gallon tank and I have 12 fish in there.  They are young South American cichlids.  I am very diligent about my water changes.  Keeping the sand clean from waste and testing the water.   I made sure the tank was completely cycled before buying fish.  

I think that’s what I was doing. I was cleaning the sponges too much, even though I was using tank water.  I have never cleaned the actual filter and it’s pretty gross but watching videos, that is how is should be 

[JettsPapa]

On 9/6/2023 at 9:01 AM, Denise T said:

I don’t put new sponges in.  I put back all the sponges. I rinsed in the tank water back into my tank.    I also have purigen and phosguard in my filter. The only think I put In new, is the filter floss.  
I have a 75 gallon tank and I have 12 fish in there.  They are young South American cichlids.  I am very diligent about my water changes.  Keeping the sand clean from waste and testing the water.   I made sure the tank was completely cycled before buying fish.  

I think that’s what I was doing. I was cleaning the sponges too much, even though I was using tank water.  I have never cleaned the actual filter and it’s pretty gross but watching videos, that is how is should be 

So the gunk that came out of the filter media went back into the tank?  That's what it sounds like.  If yes, you should discard that water and add fresh water back into the tank.  Most people rinse their filter media in a bucket when doing water changes.

[Denise T]

I don’t put the old tank water back in the tank.  I just rinse the filter media in the old tank water.  I use new water when I do a water change. Here is a picture of my tank. 

[Pepere]

Seems like you just need time for bacteria recovery/ growth…

keeping up with water changes,  And maybe only feed once, lightly, every other day until levels subside…

 

reduced feeding reduces the ammonia being added to the tank which will also reduce nitrite levels…. 
 

 

Edited September 6 by Pepere

[Rube_Goldfish]

@Denise T, welcome to the forum! I don't have anything more to add than what's been said already, and it seems you've got a good plan and setup going forward too, but I just wanted to say that your tank looks great!