• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Tank Crash?

CrazyCory42

CrazyCory42

Member
Joined
22 Oct 2020
Messages
41
Location
Tamworth
I’ve got a 100L tank, been set up for about 3 years now. I came home yesterday to find a dead julii cat fish at the surface, checked the water and the ammonia is spiking! So I did a water change, thought all was well. Come home today to find half the shrimp colony up at the surface. Check the water again and the ammonia is at 8ppm! The highest I’ve ever seen it. So I’m currently doing a water change and I’ll do another before bed.

But what’s going on. I’ve check high and low and I can’t find any other bodies. I’ve not been over feeding, haven’t changed my food or water change schedule. I’m feeling so deflated and worried.

Am I right in saying I’ve just got to water change and ride this out?

Tank Specs:
100L tank (36”L x 12”D x 15”H)
Heated 24 - 25C
Fluval U5
50% weekly water change (seachem prime)

Stocking:
4 harlequin Rasboras
3 cloud minnows
2 honey gourami
3 false julii corys
3 bronze corys
1 unknown cory
100 something RCS
3 amano shrimp

Water quality (tested with API master test kit):
Ammonia 8ppm (normally is always 0ppm)
NO3 40 (Tap water sits at 40ppm)
NO2 0
 
Last edited:
Andy Pierce said:
Do you have small children or other people that might decide to 'help' you out by adding stuff (e.g. piles of food) to the tank?
Click to expand...
No I live with my parents but they don’t have anything to do with the tank and the tank has a pretty secure lid on it too so I wouldn’t have thought that anything would have been added to it.
 
Is there any chance something has died in the aquarium that you can't see that maybe causing the ammonia spike?
 
_Maq_ said:
Increased oxygen demand or decreased oxygen supply.
Click to expand...
This can always be a very real possibility. My partner recently decided to angle-down his spray bar in his tank because his floating plants (red root floaters) were being dragged under the water by the flow. He has a fluval fx4 so the flow is fairly strong. Well, it wasn't long after doing this change that he noticed his fish was up at the surface and acting weird. There was fairly moderate nitrite readings. He angled the spray bar back at the surface, and not long after everything stabilised again.

This experience has also made me realise the reason it took so long to cycle my last tank was because I wasn't aerating the tank enough. The bacteria really are oxygen-hogs.
 
xZaiox said:
The bacteria really are oxygen-hogs.
Click to expand...
In competition for oxygen, nitrifying bacteria are the losers against heterotrophic microbes. Just like you described, a seemingly "minor" change in oxygenation pattern may negatively affect nitrifiers' community with instant increase in ammonia concentration as a result. Still, we should not forget of other negative consequences of decreased levels of oxygen. Even heterotrophs are forced to anaerobic modes of operation, and various reduced compounds are produced in increased amounts. Ammonia is just one of them, sulfides are next, plus various organic by-products of anaerobic decomposition.

There's one more interesting aspect in your partner's event: He moved the spray bar but the canister filter worked without change. If majority of nitrifiers inhabited the canister - which is what most hobbyists believe - they would be seldom affected by moving the spray bar. Or, alternatively, if nitrifiers within canister filter depend so strongly on oxygen content of incoming water then we can ask what makes the filter more suitable environment for nitrifiers than the tank itself.
 
You must log in or register to reply here.
Back
Top