Restarting my rio 240l

I set up my 240 on the 23rd, it's been over a year since it was last running.

I used my old gravel which had been stored in plastic bags outdoors, it does look as if rainwater got into one of the bags as it did smell a bid but it was all washed before it went into the tank.

I added my old bogwood (some if it still hasn't sunk yet!).

The next day I had a very cloudy tank which I assume was a bacterial bloom.

On the 26th and 27th I took some water tests ( I have an API test kit) and have identical results for both days:

Ammonia - reading if between 4.0 and the 8.0 mg/l colours on the chart.
Nitrite - 1.0mg/l
Nitrate - between the 5.0 and the 10 mg/l on the colour chart.

I assumes the tank started to cycle itself using the organic matter in the gravel?

I did add some live plants on the 24th (probably a mistake but I was always told to add the plants first in the old days).

Anyway I didn't test the water yesterday now feel a bit foolish as i might have missed the nitrite spike!

Just tested the water:

Ammonia 0-0.25

Nitrite 0.50-1.0

Nitrate between 20-40

I do have a back up plan of introducing some filter media from either the cold water tank or my 48l tropical one.

Any ideas - I've never done a fishless cycle in all my fishkeeping years?

Cheers

sounds like things are going OK i would
squeeze your sponges from an other tank
in there and may be put some flake food
in there so as it breaks down it creates ammonia
to feed the good bacteria in your filter or if you
can get hold of some pure ammonia and dose
with .5ml and test after two days and see what the readings are