fish dying

[ZombiesAteMyDog]

I have a 29 gallon tank, running an aquaclear 70 HOB filter, am fully cycled, current water peramaters are 0 ammonia zero nitrite and around 15 - 20 nitrate.

current stocking as of right now 2 fancy male guppies, 6 zebra danio , 4 cory cats, 1 african dwarf frog.

I had a rough go at cycling my tank, it took well over 2 months almost 3 using 6 zebra danios and 3 cory catfish . finally got everything sorted out and cycled.

after letting it sit for a week or so, I added 5 fancy male guppys, after I did this 3 of my 3 corys died which I assumed was from the cycling process , and then over the next week or so I lost 3 of my 5 guppies, I assumed maybe it was bullying since it was all males.

I decided to add some more corys, and added 4 to bring my total number up to 5 corys, so I had 6 danio, 2 guppies, 1 ADF, and 5 corys.

just now I found one of the corys dead, and I can only see 3 of them swimming around, 1 is MIA.

I am starting to think the guppies / cory dying off is not as clear cut as I assumed, does anyone have any ideas what might be going on? I dont want to keep adding fish if there is some sort of disease going around in my tank.

1 thing I will add, 2 of the guppies were swimming very erraticly, even somewhat on their sides, and just floating around while trying to move their tails and I found them dead shortly after, the 3rd guppy that died spent an entire day before it died swimming into the current from my filter return - I thought this was odd and did some research online and saw it was just playful but now I am wondering.

any thoughts would be most appreciated.

 

[SKB]

Have you added any new decor or paint or glue? Do you use aerosol sprays around the tank? Usually fish can adapt to pH, but what's your pH? Quick drops or increases in pH can hurt fish. How do you acclimate them?

The fish might have been sick or just not 100% when you bought them either...

 

[ZombiesAteMyDog]

I acclimate by floating the bag for 10 min, then add some tank water wait 10 min add more tank water wait 10 more minutes then net the fish into the tank.

My ph is always pretty consistent right around 7.5

As for aerosols not really, I do put models together in that room using paint, model glue, and thinner, but my first corys died before I started it.

 

[ZombiesAteMyDog]

I am able to only locate 3 of my 4 remaining cory, I fear he may be dead somewhere, I am going to give it a good once over and check.

If it was a disease or sickness wouldn't my danio or the frog be sick / dying too?

 

[Crobb]

It sounds like to me you added too many fish to too small of a tank too fast. That was too many too's lol.

 

[Ac30fan]

What are u using for water testing? Strips? Or the more accurate API master test kit? How often do you test?

I'm wondering if ur nitrates are really as low as you stated.

Fish that hover near a water return could be forcing water over their gills if they're not getting sufficient oxygen.

 

[ZombiesAteMyDog]

I use the api master freshwater kit, I test about once a week, it's real hard to get a proper reading on the nitrate test, depending where I hold the tube it could be between 10 and 60.