Need help with ammonia in my QT, please

Dave-T

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I have a 38 gallon QT. I cycled it by adding Fritz Fishless Fuel to get the ammonia to 2.4 (according to my Hanna checker), and added some Fritz TurboStart. I also put a biobrick in the tank from the sump of my already cycled display tank. Ammonia was down to below .2 on the Hanna, before I added 9 small fish. Then some idiocy began. I convinced myself that the ammonia had risen two weeks later, and couldn't find my Hanna checker, so decided to do a 50% water change. And I accidentally used RODI water instead of salt when I did the water change! I immediately realized my mistake and drained the tank down to a few inches and refilled with salt water. The tank was at about 1.010 salinity for about 10 minutes. None of the fish seemed to suffer. I got a new Hanna ammonia LR checker a few days later, and tested the ammonia and it was at .52, so I added 3 capfuls of Seachem Prime, which brought the ammonia down to .24.

Now I'm on vacation but have a housesitter watching the tank. He checked the ammonia yesterday and got a reading of .7. I had him add another 3 capfuls of Prime.

So can anyone help me understand what's going on? I don't fully understand the difference between "safe" and "toxic" ammonia, and how the Hanna checker readings relate to toxic ammonia, and at what reading I should be concerned.

Did the water change kill my cycle? Could 10 minutes of low salinity water have killed my denitrifying bacteria population? I would think that that fully cycled biobrick should be able to handle the bioload in a 38 gallon tank...

Thanks!
 

vetteguy53081

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I have a 38 gallon QT. I cycled it by adding Fritz Fishless Fuel to get the ammonia to 2.4 (according to my Hanna checker), and added some Fritz TurboStart. I also put a biobrick in the tank from the sump of my already cycled display tank. Ammonia was down to below .2 on the Hanna, before I added 9 small fish. Then some idiocy began. I convinced myself that the ammonia had risen two weeks later, and couldn't find my Hanna checker, so decided to do a 50% water change. And I accidentally used RODI water instead of salt when I did the water change! I immediately realized my mistake and drained the tank down to a few inches and refilled with salt water. The tank was at about 1.010 salinity for about 10 minutes. None of the fish seemed to suffer. I got a new Hanna ammonia LR checker a few days later, and tested the ammonia and it was at .52, so I added 3 capfuls of Seachem Prime, which brought the ammonia down to .24.

Now I'm on vacation but have a housesitter watching the tank. He checked the ammonia yesterday and got a reading of .7. I had him add another 3 capfuls of Prime.

So can anyone help me understand what's going on? I don't fully understand the difference between "safe" and "toxic" ammonia, and how the Hanna checker readings relate to toxic ammonia, and at what reading I should be concerned.

Did the water change kill my cycle? Could 10 minutes of low salinity water have killed my denitrifying bacteria population? I would think that that fully cycled biobrick should be able to handle the bioload in a 38 gallon tank...

Thanks!
Prime is an alternative and not solution and you really don’t get a full cycle in a quarantine tank, reason to check ammonia during quarantine
Add micro bacter or similar to keep the brick active with denitrifiers
 

tankstudy

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I don't think your bio brick had enough bacteria to begin with. It's bacterial population density might have not been enough to handle the amount of ammonia produced by the fish and I'm basing this off the increase of ammonia over a few days.

Tanks can be cycled at varying densities of bacteria. Your display tank is cycled but based on how much ammonia is constantly present will determine it's constant density. A lot of ammonia being produced daily will mean a very high density of bacteria and vice-versa. However, when more ammonia is constantly produced than what the current bacterial population can handle, like your biorock, it's going to take some time to get those populations high enough to handle the new increase of ammonia, especially if it's multitudes more than the bacteria can handle.

You should be adding bottled bacteria over dosing prime. At this point I'd recommend pouring a good bit of bottled bacteria. You can't overdose, so the more the merrier, as any exposure to ammonia is bad for your fish. Fish can tolerate some presence but the higher you go, the more likely your going to lose fish. If you see ammonia creeping up again after a few days, do a water change to bring it down and add more bottled bacteria.

For future QT tanks, you should let ammonia zero out first before adding anything. Also if you plan to add a good bit of live stock, especially fish, you need to have the QT converting 1-2 ppm ammonia in 24 hours. If it can't convert all of that ammonia in 24 hours, the bacterial populations are not high enough yet and adding any live stock will expose them to ammonia. If you plan to put a lot of fish, you'll need to cycle the tank twice or three times so that it can convert 4 ppm ammonia in 24 hours.

-Hope this helps!
 
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Dave-T

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Thanks. I have added bacteria and will continue to do so. But do you think the 10 minutes of low salinity could have wiped out any of the bacteria? Or doing a 90% water change?
 

SteveMM62Reef

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When I change the water in my Quarantine Tank, I always use water pulled from my Display Tank. Add new Saltwater to the Display, water from the Quarantine goes down the Drain. I can do some pretty large changes on the Quarantine as the water is well conditioned and Display is much larger.
 

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9 fish at once in a 38g new system is a lot IMM.
Thanks. I have added bacteria and will continue to do so. But do you think the 10 minutes of low salinity could have wiped out any of the bacteria? Or doing a 90% water change?
If the fish are happy and behaving normally, just relax.
If ammonia to high, you’ll know!
Otherwise your cycled.
 
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Erin1971Texas

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Also remember that Prime only TEMPORARILY detoxifies ammonia, and within 24 hours will wear off completely. The ammonia will remain in the system until it's manually removed (water changes) or converted to nitrite/nitrate by bacteria. (Or used by coral as food, but in a new tank, that's an unlikely scenario).

Also, depending on what type of ammonia your kit tests for, testing in the 24 hours after adding Prime will give you meaningless results (because the ammonia is still present).
 
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LeftyReefer

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I never add ammonia to my QT tank.

I tear my QT tank down between every batch of fish. bleach it, drain it, let it dry completely and then I set it back up add some bottled bacterial, add fish.
For the first week, I'll do 25% water changes every 3 days or so and then after the first week, it's usually cycled and the water changes aren't needed unless i'm changing meds or something.

Saying that, I syphon/vacuum out my QT every other day or so to remove any waste or uneaten food so that the water quality stay high. I just add whatever amount I've vacuumed out. Only takes a minute or so to syphon the junk out and then I just top it off with fresh SW.

I find the seachem ammonia badges work quite well in a QT tank.
 
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Dave-T

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I never add ammonia to my QT tank.

I tear my QT tank down between every batch of fish. bleach it, drain it, let it dry completely and then I set it back up add some bottled bacterial, add fish.
For the first week, I'll do 25% water changes every 3 days or so and then after the first week, it's usually cycled and the water changes aren't needed unless i'm changing meds or something.

Saying that, I syphon/vacuum out my QT every other day or so to remove any waste or uneaten food so that the water quality stay high. I just add whatever amount I've vacuumed out. Only takes a minute or so to syphon the junk out and then I just top it off with fresh SW.

I find the seachem ammonia badges work quite well in a QT tank.
That sounds like a good way of doing it. How big is your QT and how many fish do you feel comfortable adding? I have a seachem badge in mine also, but I wasn’t sure if I could trust it.
 

Erin1971Texas

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That sounds like a good way of doing it. How big is your QT and how many fish do you feel comfortable adding? I have a seachem badge in mine also, but I wasn’t sure if I could trust it.
As long as you're prepared to do frequent water changes to reduce ammonia, you can theoretically add as many fish as you want...
 
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Dave-T

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Sadly, my fish sitter told me yesterday that my foxface died. The other fish seem fine. There are 3 lyretail anthias, a small pair of ocellaris clowns, a blackcap basslet, melanauris wrasse, and bluespot jawfish. There's also a pretty large mexican turbo snail in there. He's been feeding pellets 3 times a day (for the anthias), and also half a cube of mysis shrimp and a small sheet of nori for the foxface (the wrasse would also pick at it).

Seems like a lot of food, but could overfeeding have killed the foxface? I'm wondering about the ammonia.

Ammonia is at .94 according to the Hanna checker. PH is 7.6. According to this:


that gives me a toxic ammonia level of .26. That's ok, right? Or no? Should I have him do a water change?

Any other theories about what caused little foxy’s demise? I'd like to protect the other fish, and also to understand what I'm doing wrong to prevent more deaths in the future!

Thanks.
 
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