Ammonia Readings

Question
Hi Michael,

I have two tanks and have posted on my 55 gallon tank, but now am having an issue on my 20 gallon.  

I had a fry from my silver Mollies about 2 weeks ago (13.)  The same pair had a fry of 7 3 months prior to that.  When the new babes were born, I moved the 3 month old Mollies to the 55 gallon tank, but due to someone finding them interesting prey at night, lost 3 and moved the remaining 4 back and they have since recovered.

I'm trying to provide as much detail as possible, so please excuse the wordiness!

Anyway, after the fry of 13 were born, the ammonia in the tank started to climb.  It has not gone down and sits at 8 ppm since shortly after the fry were born.   I know it's toxic so I have been doing 20% water changes every other day for a week to attempt to bring this level down (total of 3 in the last 7 days.)  Two days ago I added 10 ml of API's Ammono Lock and removed the carbon filter, cycled for 24 hrs and replaced the filter the next morning. I have also reduced feeding to 1 x day (fish not at all happy) and vacuumed the gravel.

My readings are:
Ammonia - 8 ppm
Nitrites - 0 ppm
Nitrates - 20 ppm
pH 7.6

I know the tank is over crowded, but am at a loss.  Can't move the fish to the 55 gallon cause they were getting injured.

In the tank are 13 babies - 4 3.5 month old Mollies, 3 adult Mollies, 1 dwarf guarami and a loach.

suggestions?

Many thanks
Maryann

Answer
Maryann,
it is possible to change more than the volume of the tank and still have high readings, eventually the levels will decrease.
As the ammonia decreases the nitrates will increase so watch those as well.
I would do 10% daily on the water changes less stress on the fish that way.
Keep the temp around 78-80 and feed less more often, with babies several times a day is the way is should go.
Make sure they and the adults have some green to eat as well.
If you have any further questions, just ask.