New Tank - Does bacterial bloom mean the tank is not cycled

[PaigeIs]

Hi! Me again  🙂   

I have a new 20 g planted tank and am doing a fishless cycle using Fritzzyme and Ammonia to start things off.  A bacterial bloom developed on day 1.  I've done nothing about it.  The tank has both a sponge filter and an HOB filter.  As of today, ammonia is 0, nitrite is 0, nitrate is 10, but the water is still cloudy. I've included an image so you can see how cloudy the water is.

My questions...  Before I add fish (1 to start, a molly we hate because he's a jerk)....  should I wait for the water to clear?  Do I need to do a water change?   

Edited February 4, 2022 by PaigeIs

[Guppysnail]

That bacterial bloom sucks up a ton of oxygen. It’s not outright harmful however at night plants release co2 and consume o2. Bacterial bloom consumes o2 and release co2. You subject the fish to low o2 and higher co2 which is not great for them. It will clear on its own. Excess water changes can prolong this. Once all the excess nutrients are consumed(currently they are eating the ammonia and nitrite vs you Ben bact in filters and adhered to surfaces consuming it). It will clear. Hope that helps. 

Also adding fish now will increase and prolong the bloom

[modified lung]

The bacteria bloom means there's a lot of excess complex carbon in the system. This is really common in new aquariums when the cycle isn't complete. The bloom eats carbon and ammonia too but it's very unstable and short term.

You just have to wait for the bloom to run out of carbon to eat, then the nitrifying bacteria you want will start growing faster because those don't need the same type of carbon and they'll have less competition for ammonia. Doing a water change could add more carbon and make the bloom last longer.

You don't want to add fish right now. Blooms suck up oxygen like crazy and when the bloom suddenly disappears, you'll have a big ammonia spike.

You just have to wait it out and keep adding ammonia like you did.

Edited February 4, 2022 by modified lung

[PaigeIs]

On 2/4/2022 at 3:11 PM, Guppysnail said:

That bacterial bloom sucks up a ton of oxygen. It’s not outright harmful however at night plants release co2 and consume o2. Bacterial bloom consumes o2 and release co2. You subject the fish to low o2 and higher co2 which is not great for them. It will clear on its own. Excess water changes can prolong this. Once all the excess nutrients are consumed(currently they are eating the ammonia and nitrite vs you Ben bact in filters and adhered to surfaces consuming it). It will clear. Hope that helps. 

Also adding fish now will increase and prolong the bloom

Thank you.  That's super helpful.  I'll keep monitoring the water and wait for the bloom to go away on its own.  The molly is a jerk, but I don't want to suffocate it.  

On 2/4/2022 at 3:29 PM, modified lung said:

The bacteria bloom means there's a lot of excess complex carbon in the system. This is really common in new aquariums when the cycle isn't complete. The bloom eats carbon and ammonia too but it's very unstable and short term.

You just have to wait for the bloom to run out of carbon to eat, then the nitrifying bacteria you want will start growing faster because those don't need the same type of carbon and they'll have less competition for ammonia. Doing a water change could add more carbon and make the bloom last longer.

You don't want to add fish right now. Blooms suck up oxygen like crazy and when the bloom suddenly disappears, you'll have a big ammonia spike.

You just have to wait it out and keep adding ammonia like you did.

Keep adding ammonia?   

[modified lung]

@PaigeIs bacteria blooms happen when you have something like 20 time more complex carbons than nitrogens in your system. Not sure if I'm remembering that number right. As long as you stay below the recommended 2 ppm ammonia it should be fine. Or you can pause on the ammonia for a while if you feel more comfortable with that. I'm not sure if one would be better than the other really. 

[PaigeIs]

This has all been very helpful.  There aren't any fish in the water, so I'll feed the tank some ammonia and watch the numbers and wait for the water to clear.  

[PaigeIs]

On 2/4/2022 at 5:49 PM, modified lung said:

@PaigeIs bacteria blooms happen when you have something like 20 time more complex carbons than nitrogens in your system. Not sure if I'm remembering that number right. As long as you stay below the recommended 2 ppm ammonia it should be fine. Or you can pause on the ammonia for a while if you feel more comfortable with that. I'm not sure if one would be better than the other really. 

@modified lungI wanted to thank you again for the advice.  Despite my impatience, I did northing and finally the tank has cleared on its own.  Now just waiting for nitrites to drop and it will be fish time!    

Edited February 12, 2022 by PaigeIs

[modified lung]

@PaigeIs no problem. Glad it worked out. Hopefully the tank will only need a few more days.