Tank that won’t cycle

[ButterstheAngel]

Hello I’ve had my 20g tank since July 7. The ammonia was very low, along with no nitrites, 6.8 pH and safe amount of nitrates up until 2 days ago. I did a 25% water change after a week of not doing one and later that day had a nitrite spike- no more nitrates, high ammonia, pH is hard to keep at 6.8. Besides the water change- that day I added a few small panda corys. I’ve had a 3” angelfish in here all along with a baby pleco.

My tank seemed to be almost 100% cycled and the one day I did the change and added some corys threw everything off, what gives?! The water had been salted at 1 tsp per gallon for angels fin rot. The water is foggy.

Should I continue water changes daily until it clears? I’m afraid to lose bacteria since I know it’s still in there I didn’t clean out anything just did a 25% change.

Should I just leave the water alone and let it clear?
​
Please help!

 

[Aiken Drum]

There is no such thing as being 100% cycled.

You can be cycled enough to process out the ammonia your tank produces, but if you increase the amount of ammonia, by for instance adding more fish, your cycle needs time to catch up to the increased bioload. You havent said how many corys you added, but lets say its 3 new fish. That would double the amount of ammonia going into the tank.

Water changes shouldn't effect your cycle. The bacteria responsible for your cycle lives on surfaces, not in the water. Your target should be to keep ammonia + nitrite no higher than 0.5ppm combined by doing water changes to bring it to this target if your testing shows you are exceeding it.

The cloudy water is likely a biological bloom. Its bacteria feeding on nutrient imbalances and is normal in a newly establishing tank. It typically goes away on its own in a week or two. As long as it doesn't last too long its harmless.

 

[ButterstheAngel]

So you do recommend I do more water changes until the ammonia goes down naturally?

 

[Aiken Drum]

I dont know. What are your water parameters at the moment?

As per post #6 on your other thread do whatever water changes you need to do to keep water at the 0.5ppm combined target.

https://www.aquariumadvice.com/forums/f17/sick-angelfish-379983.html#post3576621

 

[ButterstheAngel]

High ammonia high nitrite salted water. Ok I’ll do the change, thank you

 

[Aiken Drum]

High doesnt really mean anything. What are the numbers in ppm?

High could mean 5ppm or 1ppm and would require a very different level of intervention. If your test kit doesnt show actual numbers i would get one that does and change 50% of the water until you get a better test kit.

 

[ButterstheAngel]

Ammonia is 0.5-1 and nitrites are 2

 

[Aiken Drum]

I would do 3 x 50% water changes a couple of hours apart. That should get you below the 0.5ppm ammonia + nitrite combined target.

 

[ButterstheAngel]

Ok thank you

 

[ButterstheAngel]

I did a 50% change and added prime, bacteria, and salt back. My ammonia is 0.25 and nitrites are 0.25 now. I can do another in 6-8 hours because I’m working.

 

[Aiken Drum]

If you are down to 0.25ppm ammonia and nitrite thats fine. That would mean your parameters werent at the high levels you previously reported. Change half the water, remove half the waste.

 

[ButterstheAngel]

It’s back to 2ppm nitrite today even after another 25% water change again last night. Wierd part is zero ammonia. This means I have nitrosomonas but not nitrobacter, right? I’ll continue with water changes to keep nitrites down today. I’m so afraid it’s preventing bacteria growth, should I just dose with Prime for nitrites instead since ammonia is better?

 

[Aiken Drum]

Nitrosomonas and nitrobacter are just some of the many types of denitriying microorganisms. Probably not even the ones that do most of the work. There is a lot of new knowledge on the subject, new microbes being discovered responsible for ammonia oxidisation. Some of these arent bacterial. More accurate to not name specific bacteria.

The only surefire way to make ammonia and nitrite safe is water changes. Seachem make claims that Prime will detoxify ammonia, nitrite and nitrate, but particularly with nitrite and nitrate i would take that with a pinch of salt.

Seachem have nothing but anecdotal evidence that it does what they say. Their own website admits the product wasnt developed to detoxify nitrite and nitrate, they have no idea how it does this if indeed it does, and they base their claim 100% on anecdotal claims that fish sometimes survive where they wouldnt be expected to. Its up to you of course, but i wouldnt rely on that put the health of my fish in a product when i can just change some water and 100% know the water is safer than it was before the water change. Using Prime to detoxify waste should an extra measure, not the main method of keeping things safe.

0.5ppm ammonia and/ or nitrite is enough to cycle a tank and is relatively safe for fish.

 

[ButterstheAngel]

Do you think I should get rid of the baby corys since 4 days ago all was well and that’s the only thing that caused the spike. Or just continue to try to keep up with water changes and hopefully bacteria catches up to the bioload sooner than later?

Thanks for the info on Prime and you’re right- physical changes will trump a chemical that isn’t proven to work. Salt and/or Prime must be binding though because my fish seem well and nitrites are back to 2ppm.

 

[Aiken Drum]

Nitrite isnt something that will kill fish quickly or even cause symptoms for quite some time. I think thats where seachems claims stem from. People saying their fish are fine and they've been in high nitrite with prime. Its only a month or two later that they see issues and by that time they are cycled and their issues arent put down to what was happening a couple of months ago.

No. I dont think you should return the fish. You need to cycle your tank. The only way to do this is to gradually increase the number of fish. If you return the fish you will only be back in the same place when you decide again to get more fish. If you keep monitoring your water parameters daily, changing water as needed, your tank will cycle safely. When you are consistently seeing low (or zero) ammonia and nitrite add a few more fish. Rinse and repeat until your tank is stocked. Thats what a fish in cycle is. It may take a while, but it is what it is.

 

[ButterstheAngel]

You’ve been very helpful and I appreciate it!

 

[ButterstheAngel]

Problem with this method is that the nitrites don’t stay low long at all. I can’t keep doing water changes all day. I did it this morning and they were 0.25 and midday now it’s already back up to 2! I think I need less fish in the tank and then go back to introducing them 1 or 2 at a time more slowly…

 

[Aiken Drum]

I would check your tap water for ammonia. If your tap water is chloramine treated rather than chlorine treated this would be an ammonia source which would be adding ammonia every time you do a water change.

Cut back on feeding to once every 2 days. Make sure you arent leaving uneaten food in the tank.

Yes reducing bioload will help and then rebuild it up again slowly.

 

[ButterstheAngel]

It’s not ammonia. That’s at zero always now after I treat the tap. Tap is 8 pH 0 nitrite 1 ammonia. Tank’s 2ppm nitrites hours after the water change.

Tiny wafer pieces for corys and bloodworms for angel- conservative. Every 24-48hrs

 

[Aiken Drum]

Ammonia turns to nitrite. Reducing ammonia going in will reduce nitrite coming out.

You are seeing ammonia at 1ppm from your tap, so your water is chloramine treated. That will be turning to nitrite, which is why the nitrite rises shortly after a water change.

Given that, unless you are willing to return all your fish and start over with a fishless cycle, you have 2 options.

1. Stop doing so many water changes and just accept the fish will be living in waste until your tank cycles.
2. Keep on doing what you are doing, regularly bring nitrite down through your water changes, and accept its going to keep going up until your cycle establishes. Do this daily so they are periodically getting clean water and it will prevent it going above the levels you are currently seeing.

Reducing the amount of fish in the tank wont really achieve very much. There is more ammonia coming out of your tap than your fish are producing.