cycling with out fish question

[blaindugan]

- filled 40 gallon aquarium little over 3 weeks ago
Started off by adding fish food to start the cycle but after a week of testing for ammonia with none showing up I went out and bought some pure ammonia(free of perfumes, soup, etc)
Tanks temp- 85 degrees with lots of surface agitation and a power head for circulation.
- added to much ammonia. Levels was off the charts so I did a very large water change. (50%)
- put filter media and rocks from established tank in 40 g
- 2 days later tank began to test positive for nitrites.
Began adding around a teaspoon of ammonia daily
- after a week nitrite levels were off the chart and tank tested positive for nitrates
Cut back daily dosage of ammonia by half for three days( during these days I ran out of test strips but then went out and bought the api master test kit which I find to.be alot more accurate )
water chemistry 2 days ago-
Ammonia - 8ppm
nitrite - 0 ppm
nitrate - 30 ppm

After seeing how high the ammonia level was I haven't added any since I got the master test kit.

Todays water chemistry -

Ammonia - 4 ppm
Nitrite - 0
Nitrate - 40ppm

So I am a little confused and almost feel as if I added to much ammonia and messed up the cycle. I know a tanks said to be cycled if you add enough to make it 5ppm and then 12-16 hours later you don't have ammonia or nitrite in your tank. It has taken 2 days for the ammonia level to go down 4 ppm. Any suggestions as to what I should do? Is this normal or abnormal?
I would rather not start over since I use de ionized water and the replacement cartridges are expensive

 

[Celes]

I think you're looking fine. Just wait till your bacteria catch up and your ammonia levels are 0 ppm, then do a large water change to lower the nitrate levels, and then you should be ready to stock.

 

[rufioman]

^exactly

 

[Coler]

its moving on nicely - you don't need any more ammonia, and as nitrates have appeared you can take it that you have the necesssary bacteria in decent amounts.

As the guys above said, its now a question of observing the ammonia and nitrite fall to 0, then a very large water change and add fishies.

You should check your supply water so you know your base nitrate level as well - although it would be surprising if that was 30 or 40 ppm.

And welcome to the site and kudos for doing a non-fish cycle.

 

[Dr. Awkward]

Since you are using deionized water I'd recommend continuing to add fish food to the tank as a source of phosphates. The cycle will take forever and a day if the bacteria don't have access to phosphates.