Cycling with low pH fish in

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madeleinep48

Aquarium Advice Newbie
Joined
Jun 1, 2024
Messages
2
Location
Minneapolis
I’m doing an emergency fish-in cycle on a rescue betta, 5.5 gallon tank that’s been set up for two weeks now.

The past 4 days it’s been testing at 1ppm ammonia, 0 nitrites 0 nitrates. I’ve read that at my pH of 6.4, 1.0ppm ammonia isn’t toxic because it’s ammonium. I use RODI water that I’ve been adding a little bit of Salty Shrimp, but my KH is still around 1-2.

I’m using UNS controsoil which I added a week ago and has lowered pH to 6.4. I’ve read that a lower pH can slow or stop the cycling process. I’m wondering if I just need to be more patient or should try adding a bag of crushed coral in the filter to help raise pH and KH slightly for the cycle, in addition when to do water changes if 1ppm ammonia isn’t toxic to the fish, when to do water changes to help the cycle progress.

Planted, 78F, small sponge filter and Aquaclear 30 that I added 5 days ago, one piece of driftwood and one dragon stone.

The betta is a happy fella, starting to get his color back, fins growing a little, always begging for food
 
Everything you have said is correct.

In acidic water, 1ppm of ammonia isnt going to be toxic. I would still get it down to 0.5ppm with a water change. Your water chemistry is going to fluctuate while establishing, the pH might unexpectedly rise or the ammonia might unexpectedly rise. Keeping ammonia no higher than 0.5ppm gives you a safety net against one or both of those happening.

At such a low pH and KH the growth of the microbes responsible will slow down and it will take longer to cycle. 2 weeks isnt long enough for a tank to cycle in optimal conditions though, so you need a little patience. It could easily take several months.

Its up to you really. Increasing the KH will probably speed things up, might still take months though. But on the flip side, increasing the KH will also increase the pH which will make the ammonia more toxic.

Personally, if you dont need to muck about with water chemistry i wouldnt and if you keep ammonia + nitrite combined below 0.5ppm there is no risk.
 
Everything you have said is correct.

In acidic water, 1ppm of ammonia isnt going to be toxic. I would still get it down to 0.5ppm with a water change. Your water chemistry is going to fluctuate while establishing, the pH might unexpectedly rise or the ammonia might unexpectedly rise. Keeping ammonia no higher than 0.5ppm gives you a safety net against one or both of those happening.

At such a low pH and KH the growth of the microbes responsible will slow down and it will take longer to cycle. 2 weeks isnt long enough for a tank to cycle in optimal conditions though, so you need a little patience. It could easily take several months.

Its up to you really. Increasing the KH will probably speed things up, might still take months though. But on the flip side, increasing the KH will also increase the pH which will make the ammonia more toxic.

Personally, if you dont need to muck about with water chemistry i wouldnt and if you keep ammonia + nitrite combined below 0.5ppm there is no risk.
Alright thank you! I wasn’t sure about when to do water changes because controsoil can release some ammonia so I didn’t want to take it out in case it’s ammonia vs ammonium. I did get a LFS to give me a bag of their squeezed sponge media so I was hoping that would help a little. I’m going out of town for 5 days so I’ll do a water change before I leave and not feed the fish every day to keep the parameters more stable, then I’d consider adding something to increase KH and pH.
 
If you are going away and wont be able to test or do water changes for a few days i would get the ammonia as close to zero as you can before you go. Do 3 or 4 x 50% water changes the day before you go away.
 
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