I have a three month old 26g tank (full details below).
It was stocked with a half dozen neon tetras, four peppered corries and a pair of dwarf gourami's.
I was out of town for three days last week. The fish were all well fed, and I'd hoped they'd make it through the three days without feeding. I returned to find a dead cory attached tot he filter intake.
I did a midweek test using a test strip.
Nitrates are negligible, i.e. well under 20ppm the first color on the comparison chart.
KH between 0 and 40
I then did a 50% water change.
I put the death down to stress from us being away. Next day we were at the pet shop and so I replaced the cory and added 2 oto's.
Over the next two days a neon tetra and the new cory died. That was two days ago.
Another water test has shown the same results. The fish appear to be acting normally. The tetras are schooling. The corries switch between resting and foraging vigorously. The gouramis continue to assert themselves.
Should I be doing anything differently? Is it likely the fish just failed to cope with stress from a few days not being fed? The new cory was tiny so I'm guessing very young and may also not have adapted well to the move.
My second question was about feeding. The Oto's look great and cleared any and all algae from the tank in 24h. I added a slice of zucchini which they appeared to find and start work on. It was about 1/4" thick and was boiled for 2 minutes. After about 24h, the gourami's discovered this too. At 36h it was almost gone.
I'm guessing the gourami's ate most of it. Should I be concerned about them overeating? They're certainly voracious. They'll often follow the cory catfish to see if they have found anything worth eating. Are there any tips to ensure the oto's get fed without the gourami's over-feeding?
== Tank setup ==
1. What is the size of your tank?
2. What are your water parameters? State the brand of test kit used.
As above. Quick Dip test strips.
3. Is your aquarium set up freshwater or brackish water?
4. How long the aquarium has been set up?
5. What fish do you have? How many are in your tank? How big are they? How long have you had them?
2 dwarf gourami
5 neon tetas
3 peppered cory
6. Were the fish placed under quarantine period (minus the first batch from the point wherein the tank is ready to accommodate the inhabitants)?
7. What temperature is the tank water currently?
8. Are there live plants in the aquarium?
9. What filter are you using? State brand, maintenance routine and power capacity.
aqueon 30. Carbon filter changed monthly.
10. Any other equipment used (aside from heater and filter which are two very important components of the tank)?
11. Does your aquarium receive natural sunlight at any given part of the day? What is your lighting schedule (assuming you do not rely on sunlight for our viewing pleasure)?
Natural light from north facing window. Aquarium light on ~12h/day
12. When did you perform your last water change and how much water was changed? How often do you change your water? Do you vacuum the substrate?
50% change as above.
Been reducing water changes after cycle completed. Currently change 4g twice a week.
13. What foods do you provide your fish? What is the feeding schedule?
Flakes with occasional dried bloodworm. Usually feed what is eaten in about 30-45 seconds twice daily.
1 shrimp pellet daily for catfish. Usually broken up, otherwise the gourami's will eat it all.
14. What unusual signs have you observed in your fish?
15. Have you treated your fish ahead of diagnosis? If so, what treatments did you use? State your reasons for planning ahead of proper diagnosis.