unwritten is correct about the employees though I tend to agree that the nitrate tests aren't needed.
Good advice about listening to employees in lfs', but actually the nitrate test is needed. First, you know your tank is cycled when ammonia and nitrite remain at zero and you have a nitrate reading. Secondly, you test for nitrates for a while to determine a good water change schedule for your tank, and also when something happens you test for all three.
My guess on the cloudy water is that you are doing too many water changes. I would reduce the wc's if your tank has already completed its cycle.
I can't really see how more water changes could possibly cause cloudiness...?
Also, if it is a
white cloudiness it is a
good thing, it is a population explosion of the bacteria that eat ammonia and nitrite. Don't try to get rid of it. Look at it as a good sign, smile, and wait it out. It will clear up when there are plenty of good bacteria in the tank.
I assume it didn't though and that you are doing a "fish-in cycle" in which case continue your wc's and know that your fish will become stressed/sick and most likely will not make it through the cycling process. (maybe the gouramis will make it)
Ammonia may be at safe level NOW but that is going to climb higher before it is truly at a safe level. Then nitrites will do the same. Both are toxic to fish.
Doing the fish-in cycle will make the process of cycling take longer because you are doing those wc's.
That's okay, though, because the water changes are what will save your fish, or at least minimize losses. Also, if the tank has been up for some weeks, ammonia may have already peaked and nitrites may already be the problem. Only by testing for the big three can you tell for sure.
If I were you I'd buy the tests, do some reading on cycling, and definately wait before adding more fish. At this point you don't have to give up on fish-keeping. Its a great experience once you are equipped with the facts.
Also, there is bottled bacteria you can buy from your lfs. Adding it may help in this case (you wouldn't have to do so many wc's) and it is inexpensive.
It won't cycle your tank quicker but it would help the fish because it would eat the ammonia. They'd still be subjected to nitrites so keep testing.
Look for articles, links and stickies regarding "fish-in" cycle for more accurate and trustworthy information.
Good advice on researching and waiting.
Something else you can do is if you know someone with an established tank, ask if they can spare a filter sponge or some sort of filter media, bring it to your tank keeping it wet during transport, and swish it in your tank, or insert it into your filter if it will fit. Introducing the beneficial bacteria into the tank actually will shorten the cycling time period. I really can't speak about the bottled bacteria additives as I have never used them.
On the subject of pH... never mind what they tell you, you do not need to monkey around with the pH. Actually that can be deadly to your fish. Leave it alone. A stable pH is much more important than a particular pH. They'll sell you ph-up, ph-down, your ph will swing wildly, your fish will get sick, they'll sell you medicine, your fish will die, they'll sell you new fish... you get the picture. The kid in the fish store probably has little to no experience with tanks, probably watched a training video in which they were told ph is vitally important... it is a sales pitch. Just smile and nod, then get the test kits you need.