I have a new tank, 100 litres, set up Dec 26 added fish Jan 5, at first it was clear now it has become a cloudy whitish, the fish have now shown signs of ick so I am treating them (2 days now) have changed the water, about 20% everyday the last few days, as per instructions on the ick med. But now the tank is showing signs of green algae on the glass of the tank.
I think I have overcrowded the tank a bit, I have 2 groumis, 2 platys, dojo, 3 snails, 1 kissing fish, 3 balck mollies, 10 neon tetras, and 9 guppies that are already having frys, I had 13 babies but 10 got eaten before I put the other babies in a breeding floater.
I went and got the six in one test strips and the results are the following rating:
Nitrate-20
Nitrite -.5
Hardness-150
Clorine-0
Alkalinity-80
PH-7.2

I can tell by your test results
That your aquarium has not finished the cycling process. (https://www.askmehelpdesk.com/other-pets-animals/aquarium-cycle-nitrogen-cycle-77553.html)
The white cloudy water is a beneficial bacterial bloom that will
Clear up as soon as the bacteria have formed colonies.
Continue to treat for ick and continue making the partial water changes.
During this time it is also important not to clean the filters or change cartridges.
This way the beneficial bacteria has a chance to form colonies.
Some ick treatments will turn the water a blue or green color and stain
Silicone and décor inside the tank.
The algae poses no health risks to your fish, so don't worry about that right now.
Let the tank finish cycling and get the fish well before
Treating for the algae problem.
You can reduce the amount of algae growth by leaving the aquarium lights off and/or moving it away from direct sunlight.

You are right about the overcrowding in the tank as well.

Please let me know how things work out.:)