My House Mate Fed my Fish...

[Red_Ribbons]

I went away for four days over the weekend and my house mate very kindly fed my fish for me. Unfortunately she put enough food in there to feed a shark and when I got back there was a weird creamy sludge over the everything, an ammonia reading approaching 8.0 and the fish were gasping at the surface.

I immediately performed a 75% water change using a gravel vacuum and have turned on the aeration function on the filter to maximum to get as much surface agitation as possible (the water had gone so cloudy I could barely see anything in the tank. I guessed that was some sort of bacterial bloom). Today the ammonia reading was 1.0 and the water was much clearer so I did another 50% water change (again with a gravel vacuum) but ammonia is still 1.0.
The fish are active and behaving normally.

My main questions are:
1. How much damage will this have caused to the biological filter?
2. Is there even a biological filter left after the oxygen depletion?
3. How long can I expect it to take to put it right?
4. Should I rehome the fish whilst the tank rectifies itself and dose it with ammonia?

Tank details below:
Size: 6 gallon
Stock: 2 ghost shrimp and 4 pearl danios
Lightly planted
Time Running: stocked for 12 mths (the tank was fully cycled with ammonia prior to stocking)
Partial Water Changes: 25% weekly

Current Readings (tested with Liquid API Test Kit)
Ammonia: 1.0
Nitrite: 2.0
Nitrate: Between 20-40 (the test card is quite hard to read)
taken 1 hour after todays 50% water change.

NB: I already realise that this tank is considered a monstrosity and am in the process of getting a bigger one so I can increase the size of the school. Due to the size of the tank I am really particular about my water perimeters and feeding, it has been really upsetting to see it all go to pot.

I don't know which part of "Just give them a tiny pinch every other day" she didn't get but I couldn't get cross with her because she is usually really conscientious and loves animals. She's been under loads of stress lately (which may account for the misunderstanding) and would be mortified if she'd realised she'd nearly killed everything.

 

[Nils]

I would just continue doing PWC's and in the future, put the amount of food you want to be fed in little bags and hide the food container. IMO 50% water changes every day until levels are safe. Don't move the fish, might stress them to death. There should still be bacteria in your filter/substrate.

 

[Fresh2o]

In the future, prior to your next leave of absence, you could place appropriately sized portions of food in small plastic cups or ziplock baggies. Put dates on the cups/bags. And HIDE the remaining food.


Sent from my iPhone using Aquarium Advice

 

[Red_Ribbons]

Thank you for the advice! Yes, I have got them a pill box for future feeding, it's got little compartments which are labelled with the days of the week. Will continue with the water changes and it's good to know not to move them. Thanks again.

 

[sinibotia]

In the future, don't have anyone feed them at all. Fish can go weeks, sometimes months without food. You should be fine leaving your fish unfed for up to two weeks. I always told my roommates never to touch my fish.