Help! Unexplained Fish Deaths

[JesseG]

Tank: 72L Bow front
PH: 7.8
Ammonia: 0
Nitrite: 0
Nitrate: 10
KH & GH: Unknown
Temp: 78F
 
Fish appear healthy in color but are slow and lying on the bottom or on driftwood upright on their bellies like they would when they are at sleeping rest
but they are panting in breathing like they aren't getting enough oxygen, then they just eventually are rolling on their sides and die. Over the past 2 days I have lost 6 fish and 4 shrimp!!!!
I am coming up with no apparent reasons for them to be dying off and need help!
The tank has been set up over 6 months ago and was fish in cycled with tetras.
 
I run a t5 54W x 2 bulb 6700k 4" light
lightly planted ( 7 plants ( 3 @ 3" x 3" x 3" in length x width x height) ( 1 Java fern pad @ 5" x 2" x 6" ) (1  @ 2" x 2" x 8") (2 @ 3" x 2" x 4") )
3 Drift wood pieces ( 1 large, 1 medium, 1 small)
fluorite substrate 2 1/2 " deep
large air pump running 2 x 5" air stones
Fluval 306 canister filter with sponges, carbon, bio chem x 2 trays running at full output. ( out put both breaks water surface and is placed directly where one air
        stones bubbles travel in front of out put to be pushed around and broken up in the water / air diffusion point.
glass tank top with open area at back of tank where pump and air inputs and outputs enter tank.
I do 15-20 gallon water changes once a week and use gravel siphon to clean into the gravel, also cleaning the filter media. the only media yet to change is
         the carbon as I have changed piece by piece to prevent biological shock.
I have always used rain water from a rain barrel and some tap water (de chlorinated with chemicals) to add to tank.
 
I had taken out the tetras about 5 months ago and had 5 German blue rams and 10 Amano shrimp (SP?) they all seemed happy but the rams never got much color to them.
I recently added 14 assorted African Cichlids (all smaller then the rams to avoid fighting) about 2 weeks ago. (all from the same tank)
one or two of the Africans died off from fighting with each other but since stopped. all the fish rams and shrimp included swam together and got along with little to no fighting.
suddenly they just started dying off, first went 2 Africans, then 1 more African, then a ram, then 1 more African, and one more African was taking its last breaths when I got home and decided to ask for help.
the fish haven't been left dead in the tank more than a few hours at most depending when they died.
all the fish look healthy and have no visual sicknesses.
I feed them once a day and alternate between flakes, cichlid pellets (small), and frozen blood worms.
I recently (4 days ago) started on a new pack of frozen bloodworms. Thinking the blood worms could be the culprit, I stopped using them yesterday and did an unscheduled
                  20 gallon water change and added a bit of cycle to the tank.
still today as I posted, a fish died this morning and one when I got home from work.
 
I am tapped out for ideas and need a bit of guidance as I have had many tanks before and never as much trouble as I've had with this one. could it be lack of oxygen, bad blood worms, need new carbon faster, rain barrel water, sickness?   any ideas for me anyone?
 
I can provide more info if needed but I tried to be very clear.

 

[Mamashack]

Can you just clarify the size of the tank because at the beginning you say it's a 70L and then later you mention 15-20G water change?

 

[catfish4ever]

70 litres is farrr to small for those fish,

Edit: he means 72 gallons XD I'm pretty sure rams need a lower pH and soft acidic waters? Considering African cichlids love hard water and high pH I presume the fish aren't compatible

 

[JesseG]

sorry guys, 72 Gallon Bow Front.
As for the rams, I was running a 6.8 PH when I had just them in the tank alone (i realize it was a bit high) and did alot to keep the
ph down, so I decided to just let it
do it's thing and has slowly climbed to 7.8 now.
the rams have somewhat aclimatized to it but that is what made me get back into the africans.
I have had in previous tanks breeding rams and a variety of africans and they all got along in a 7.5 ph tank, even with clown loaches,
so I thought I'd go african and if the rams
held thier own they did.
none of the africans fight with the rams even now, fighting is definately not the issue I am having.
to add to my top water readings, i ran out and tried some test strips for gh and kh readings.
the kh came to about 40
the gh came to about 180  (or vise versa) sorry at work now.
 
even when the fish die, they are still full colored with no visible signs of sickness.
since the post last night, I have changed out my carbon and run some peat through the filter to assist with the high hardness readings.
still this morning, 1 ram and 1 african that looked sluggish last night were dead.
i did alot of reaserch and the closest thing I could find was Malawai (SP?) Bloat. yet they don't seem at all bloated.
the symptoms are
1: stop eating
2: lazy and near bottom of the tank
3: start resting thier bodies upright but touching the gravel
4: heavy breathing like they are oxygen deprived yet there is more air going into that tank then even i could consume
5: start rocking side to side when they try to swim and even kinda float with the current in the tank and even tip head up or head down
6: laze back at the bottom until they just die.

 

[tonydb]

Hi sorry to hear this,
 
I've had the same problem recently ,11 fish died ,with no explanation,over the coarse of about a week.The only thing i had changed was my heater as the original one was broken.Then once they started dying i removed my danios took them to the store to save them.
 
Speaking to the chap that runs my local store, we put it down to the extreme hot weather we have had in the Midlands coupled with my new heater heating up the water,so basically i boiled them to death.I only had the heater on 26 ish , but with the heat from outside must of been hitting 29 ish i reckon.
 
Since i have now turned my heater down a little and my water is sitting on a steady 25-26 with the lamps on.
 
Perhaps this is the same cause as to your little fishes dying.

 

[JesseG]

Thanks Tony for the suggestions however, we have also been getting some hot weather, so as it started to warm up, I actually shut off
my heaters completely. I have a stick on temperature reader and it hovers around 77-80 (25-27). I haven't had the heaters on for about a month.
they are still dropping one by one, I started with roughly 15 fish and am now down to about 4-5. I noticed however that in my original post
I mentioned that the shrimp were dying however I found it to be molts.
the shrimp in the tank actually seem to be doing great and despite my original post, I actually haven't lost any of them.
I have done a couple of water changes and removed 4 of the 7 plants (in case oxygen reasons)
on day 3 of a 7 day bacterial treatment (which seems to be no help)
I didn't feed them for a day to see if they may have had a problem with that but today they aren't even interested in food.
 
still the only thing that I can think of that changed is 2 days before they all started to die off I finished a blood worm pack and
started on a new pack (they all love it so I do a bit here and there not their main food)
 
has anyone ever heard of contaminated bloodworms they are the sally brand frozen. that is the only thing I can even think of
to point my finger at by now is that the bloodworms could have had some kind of disease. but what could it be that it affects my fish
and not my shrimp???