I should mention I live in the UK so the products I am using may only be avaible in the UK.
Me too, so I know of what you speak.
To test the water I use API liqiud tests, they are the only brand of liquid tests sold at pet shops and aquariums store I spent a few minutes checking before buying the products.
Good.
The ammonia remover product used is called Interpet, it does seem to work as before I carried out my last water change the ammonia level was 0.25ppm and after the change and adding of this product it came back as 0ppm.
The only way I know of 'instantly' removing ammonia using a product like this is if it binds with the ammonia to make it safe for the fish. However 24-48 hours later the ammonia will be released again if the filter isn't able to process it before then. The point here is that you changed the water and so (unless your water has ammonia in it) you'd fully expect the ammonia reading to be zero.
The waste control brand is Nutrafin, I only brought it because I thought the cloudiness was caused by a build up of waste and this product was reccommend. It does have the side effect of increasing the ammonia levels but as I mention before the ammonia remover I use seems to work as the results come back as 0ppm.
At least you're aware of the fact that this type of product increases ammonia, many aren't. However, if your tank is full of organic matter and your problem is high ammonia you don't want to add to the problem by using this stuff. Despite what you're saying about the efforts you're going to to keep the tanks clean I still suspect that it's collected muck etc in the gravel and/or filter that's causing this problem (that in turn being due to being overstocked).
The couldiness occurred before I started using the waste control product, since using the product and spending longer cleaning the gravel I'm not kicking up as much muck I would say properly just a few debris and coming up when I desiturb it.
The water is sort of a milky white colour, when you look really closely with the light on I've notices there seems to be these really tiny particles floating around in the water. I've also noticed that when I carry out large water changes the water clears a bit for the 1st day or 2 and then it becomes really cloudy again.
That's almost certainly a bacterial boom then. As I've already said there's only a few causes for that: under filtered, under maintained, overstocked or your filter isn't cycled.
I don't know if this helps but I got the rest of the liquids tests needed to test pH, nitrites and nitrates levels. For the 60l tank only the pH level was slightly elevated, it came back as a pH of 7.6. The rest of the tests came back at the recommended 0ppm. The 15l tanks nitrite levels came back as 0.25ppm.
The ammonia is elevated as expected, the pH isn't relevant for your problem.
I'm carrying out a water change on both tanks so hopefully they will go back down and I intend to buy a bottle pH Down and Stress Zyme to help if there is still an issue with these two levels.
No,no,no!
Please don't buy any more chemical products, it's money down the drain and would be better spent getting a bigger tank off eBay. You're trying to fix a bleeding wound by bandaging it rather than doing what you should be doing which is stitching the wound.
I hope this helps and I'm really sorry if I sound like a complete pain.
This is what the forum's for.