Hlp! High Nitrate Readings On A 5Mth Old Tank

[carmstrong]

Hello everyone, 
 
I have a question regarding a friends tank. 
 
My friend has had her tank for 5mths now and she is having high nitrAte reading 24hrs after a 50% water change. 
 
The tank is a 10g currently stocked with the following:
1 Dwarf Gourami
2 Scissor Tail Danios
2 Zebra Danios
1 Lepoard Danio
1 ADF
And a bunch of Mystery Snails that have procreated a football team. current count.. 17
 
Yes we are aware its overstocked...
 
Now we did a water changed last night of 50% of the tank and then tested the water 24hrs later as well as did a water change of 40% the night before. 
NitAte readings:
1st reading was 120ppm
2nd reading was 80ppm
3rd reading 60 mins later was 40ppm. 
 
Now I suspect that the snails as they grow are throwing the tank into a hyper cycle and causing the NitrAte levels to rise rapidly. 
 
I tested the Ammonia and Nitrite levels all two times and these were the results. 
1st reading:
Ammonia .25ppm
Nitrite 0ppm
 
2nd reading:
Ammonia 0ppm
Nitrite 0ppm
 
Any advice you may have would be appreciated, she's had to empty the tank every other day to keep up. 
 
Thanks in advance!

 

[Chad]

Yes we are aware its overstocked...

In this sense you answer your own question about cause.
 
There are a few solutions I recommend.

1. Remove some fish.
2. Do more frequent and deeper water changes.
3. Feed less and/or less often (depending on livestock needs).
4. Upgrade to a larger tank to accommodate the livestock.
5. Deep clean or replace the substrate to remove trapped detritus. 

There might be a few other ideas out there. For quick management the water changes are the place to start.