Lost 3 Fish In 8 Hours.

[redskygrave]

Ok I got a serious problem and I don't know how to fix it.
 
Had a 10 gallon with 4 guppies and 2 platies in it. Last night I found one guppy dead on the filter; I then found a platy dead on the filter; and now just a few minutes ago; found a guppy floating on the top. 
 
I checked the water conditions: A:0, Nitrite:0, Nitrate: 10, Hardness: 120, and the PH is 7.8.
 
The fish are all swimming at the top of the aquarium and look like they are gasping for air. I have a 30 gallon air pump blowing air in through 2 airstones located at both sides of the tank.
 
I don't know what's going on but I need to save my fish. Help!

 

[fluttermoth]

Ok, it doesn't look like there's anything wrong with your water, but there are loads of things we can't/don't test for that could be affecting your fish, so you should do as big a water change as soon you can.
 
Make sure the new water is warmed, and add a double dose of dechlorinator. Make sure all your electrics are working and that your filter's not blocked; but don't overclean it (you don't want to disturb your bacteria too much).
 
See how things look then and get back to us.

 

[redskygrave]

Okay, did a 50% water change. No real change in the behavior of the fish. 
 
Tested the water now and its: A:0 , Nitrate:10, Nitrite:0, Hardness: 150, Alk: 300 and PH 8. 
 
The Alk could be the problem idk... 

 

[az9]

my alk is 300 and my fish are fine.

 

[redskygrave]

Ok after the water change and upgrading the two airstones to a 18" airstrip; they seem to be doing better. They are hanging out at the top but they are coming down and swimming a bit. Got one or two that like to sit at the very top but they seem to be doing better.

 

[RCA]

Glad to hear they are doing better, but I reckon something may still not be right if they continue to hang at the top.
 
Can you tell us, what size your tank is?
What substrate (gravel etc) is in the aquarium?
Any ornaments and what are they?
How long the tank has been running i.e. set-up?
Any recent changes to the tank, or fish occupants?
What model is your filter, and how do you clean the media i.e. sponges etc?
What is the de-clorinator you use?
Do you have real, or plastic/silk plants?
 
Can you also please put your location into your profile, as there are different remedies etc., for different countries.
 
Thanks all the above will assist in helping you further.

 

[redskygrave]

They are currently in a 10 gallon (I'd like to upgrade to a 30 but gotta convince the wife)They currently use a gravel substrate though I'd like to go sand. The only ornament is a moon rock. Tank has been running for 3 months. I added 2 platies 3 weeks ago. I use a Aqua-Tech 5-15 gallon with a Bio, sponge and Carbon filtration. I use Stress Coat; and I have one plastic plant.
 
As an update for the fish: They are swimming all around the tank and more stay towards the middle/bottom again.

 

[the_lock_man]

How did you cycle the filter?

 

[redskygrave]

I rinse the sponge with my water change water; keep the bio filter in and change out the carbon out when I water change.

 

[the_lock_man]

You misunderstand me.
 
When you first set up the tank, how did you grow the bacteria colonies in your biofilter?

 

[redskygrave]

Oh! I used a tetra product that had a bacteria in it; and then used the ammonia from the fish 

 

[the_lock_man]

OK, then a possibility for your 3 deaths is delayed reaction to the ammonia, if you weren't 150% scrupulous about water changes (very few of us are, btw, so please don't take that as a criticism).

 

[This Old Spouse]

+1
 
Sometimes the effects of ammonia poisoning take a long time to show up. Your tank wasn't really cycled when you put the fish in ... the bottled bacteria is questionable at best. 

 

[redskygrave]

Yeah probably right. I do a 25% every other day, but there was times I did slack off. Of course that was before I get a syphon and its simple now xD.

 

[N0body Of The Goat]

Up the top, gasping for air is a classic symptom for nitrite poisoning or low oxygen levels. I would do another ~95% water change ASAP (even though I see you have done a ~50% since this broke out).
 
Were you using test strips or liquid test kits for your results? Test strips are infamous for false readings, as are insufficiently shaken liquid nitrate bottles. 
Could your sampling be inconclusive because of insufficient flow in the tank? I've personally experienced perfect stats in the filter flow before now and then found stats requiring a ~95% water change from a sample taken near the same tank floor.