morning deaths

Apr 24, 2011
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#1
i have a 220 gallon planted tank with 4 discus, 2 8" clown loaches, a 10" black ghost, a 12" pleco and some small cory's. the tank has been running for 10 years. i have 2 ehiem filters running on it. yesterday when i went downstairs, the black ghost was dead and one of the discus was upside down. i got him out and put him into a small tan and immediately he looked better. i did a 30% water change (as i do every 2 weeks) and everything in the tank seemed fine.
this morning the 2 clown loaches are dead and the remaining discus near death. the only thing I can think of, would be that some of the beefheart i fed last week hurt the tank (uneaten) although it certainly wasn't enough to oul a 220 or the oxygen level is depleted at night. although the jungle val seems to be taking a beating while the swords look ok. the plant break down would seem to me to be a water quality problem.
i am doing another water change now.

any ideas?
 

Feb 27, 2009
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#3
What are the readings of ammonia, nitrite and nitrate? If injecting CO2, what is your morning pH level, and midday level?

Contrary to popular belief, CO2 will not displace O2 in an aquarium, but can cause dangerous swings in pH if its level is set too high.
 

Apr 24, 2011
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#4
morning death

i don't use co2. just 8 65 watt compact fluorescent. works fine.
i have seen this problem in the past. i have been keeping fish since 1973.
i totally believe this is lack of oxygen. i did anothe 30% change today and the 2 discus i put back are doing fine. i will put an airstone in tonight.
the ehiem return tube is set so that it does not provide much agitation. the tank grows duckweed like an outdoor pond. a sign of good water quality.
 

Kiara1125

Superstar Fish
Jan 12, 2011
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Florida
#5
Yes, put more oxygen in the tank, that should help. You said that you saw this before?? If so, why is it that you didn't do anything to prevent it from happening again or did you thing it was a one time thing?? Not angry, just curious.