Need an explanation

[Ricky J]

Just diving into the sw world. Can someone please explain why adding too many fish after the cycle can lead to a bacteria bloom and kill the fish? I just don’t understand the science behind it. Does the same thing happen to an established tank (say 6-12 months)? Does the same thing happen when you add too many inverts (CUC)?

 

[Supa]

Just diving into the sw world. Can someone please explain why adding too many fish after the cycle can lead to a bacteria bloom and kill the fish? I just don’t understand the science behind it. Does the same thing happen to an established tank (say 6-12 months)? Does the same thing happen when you add too many inverts (CUC)?

I think it’s because there isn’t enough nitrifying bacteria on your rocks to turn ammonia that the fish make into nitrite then to nitrate. You can add a lot of CUC at one time. No worries.

 

[theMeat]

It’s a balancing act. Each fish is fed and poops. Bacteria that is established with a cycle is finite. This beneficial bacteria needs nutrients (food) in order to live. Too much nutrients and you don’t have enough beneficial bacteria to process it. So you slowly build or decrease your bio load to avoid swings which are toxic to life.

 

[malacoda]

Bacteria bloom from too many fish at once is news to me.

On the flip side though, I can see too many fish at once increasing the odds of an ammonia spike in a new tank.

The amount of denitrifying bacteria present will be dependent in part on the amount of food — ammonia, nitrite, nitrate — available to them.

The amount of available organic material available during cycling will in part have dictated the amount of bacteria present at the end of the cycle. If you drop a ton of fish in at once, there may not be enough bacteria present to immediately process the ammonia they produce. And the ammonia may reach levels high enough to injure/kill your livestock before the bacteria reproduce enough to match the load and process it.

But a bloom from too many fish...? Doesn't make sense to me.

 

[zheka757]

5 years ago, i started my 400g tank at that time. i wasn't testing water ether, 1 month into it i "assumed" my tank was cycled dumped 4 damsels in, 3 month after i start putting bigger fish in it. can remember when, but one day i tested water, and i had crazy high nitrites. i dosed seachem stability daily, and in 3 weeks all was well.
that was my fist mistake/lesson in salt water. test and don't rush

 

[dontbuyxenia]

The biological filter is not fully established after the cycle. Its simply the threshold needed to be able to support at least some amount of organic waste. If I dumped a lot of organic material into an established tank it would cause an ammonia spike because there is too much ammonia for the biological filter to handle. If you add too many fish after a cycle you can have the same issue. I assume that the lack of nitrifying bacteria and presents of organic material would lead to a situatiion in which there could be a bloom

 

[Ricky J]

Interesting, appreciate the feed back everyone. I believe I used the wrong terminology with the “bacteria bloom”, sorry if I threw some of you off. I believe what I was referring to was just a increase or spike in ammonia rather. But based off organic matter or organic waste, I suppose you could significantly raise the ammonia enough to kill the livestock with just the CUC?

 

[mdb_talon]

Interesting, appreciate the feed back everyone. I believe I used the wrong terminology with the “bacteria bloom”, sorry if I threw some of you off. I believe what I was referring to was just a increase or spike in ammonia rather. But based off organic matter or organic waste, I suppose you could significantly raise the ammonia enough to kill the livestock with just the CUC?

You could but unlikely unless they are dying (or you dumping in a lot of food for them)

 

[Ricky J]

Oh I see said the blind man, cause as it decomposes it releases back into the tank. A little light bulb came on there!

 

[theMeat]

Oh I see said the blind man, cause as it decomposes it releases back into the tank. A little light bulb came on there!

Rather than having a die off start small with cuc. Population will grow according to the tanks needs. Same concept as with your beneficial bacteria

 

[Ben1982]

It's because the bacteria has to increase to the new bio load. Bacteria in this case is self regulated. And as you add fish the load increases but the numbers of bacteria lags behind. It's all percentage based though adding 1 fish when you are keeping 100 already means very little but adding another fish when you only have 1 means a lot.