Help possible recycling of tank

[mindgame]

Ok so a few days ago I added ten 1-2 inch giant danios to my 75 gallon tank that contain one 13 inch red devil. Current Filtration is a fluval 405 and an ac 110 tank has been established for well over a year.

When I got home this after this weekend I noticed 2 of the danios were missing and I figured the RD picked off a few of them despite his lack of interest in the thus far. Last night my RD was acting a little weird so I broke out the test kit and everything was fine except for very high nitrates probably around 80 to 100 ppm. So I did a 25 percent water change and then decided to check and clean the fluval 405 because I had not done it in a while. I found 2 dead danios in the filter so i took them out and dipped the media in some tank water to clean some of the built up crap out of there. Then this morning when I got back from class the water was very cloudy so i tested the water again.
ammonia .025ppm
nitrate 80-100 ppm
and nitrite 0ppm

I am somewhat new to fish keeping and am wondering what my next step is?

All the fish seem fine the RD is back to his aggressive/begging for food self so Im not really sure whats going on.

Any advice would be greatly appreciated.

 

[mindgame]

Sorry if this is in the wrong place

 

[DMasker]

Your in the right place.

I am not the best at diagnosing this so please anyone feel free to correct me if I am wrong. It seems to me that you might have added too many fish too fast, which would cause a spike in ammonia by offsetting the bioload too much as once. I would do at LEAST 25% and preferably 50% water changes everyday until everything clears up in the tank. Hope this helps!

 

[mindgame]

Im changing another 25 percent of the waterchange as im writing this. Your probably right about adding to many fish to fast. I didnt think it would matter because they are so small but you are probably right.

 

[BODYDUB]

Something isn't adding up with the way you explained. The 2 danios shouldn't have thrown your tank out of cycle, and you rinsing the media out in tank water is the correct way. The only thing I can think of is that the decaying fish release toxins causing your levels to rise. But I'd do 50% every two days if your RD is your only inhabitant.......