Cloudy water and mini-spikes are not the same thing. They can be related (or unrelated) but each may have a different duration and each may happen independently.
Limiting our discussion to milky/gray cloudy water (there is also green cloudy water due to types of unattached algae, which is a totally different subject) we call this a "bacterial bloom" and the cloudiness you are seeing are the actual millions of cells of bacteria. These are mostly heterotrophic bacteria (differen species from the beneficial bacteria we try to grow in our filters.) The bacteria are feeding on some sudden abundance of some type of organic substance they can process (by contrast, our filter autotrophic bacteria process inorganic materials, not organic) and this happens frequently in new tanks. In established, older tanks it happens infrequently, usually in association with lapsed care. In new tanks it can be excess material from the glues used to construct the tank and have nothing to do with the biofilter nitrogen cycle. In old tanks it can be blooming heterotrophs feeding on excess organics stirred up in a tank where lack of care has allow excess debris to remain.
Mini-spiking refers to short-term elevated levels of the two substances that are the nemesis of fishkeeping, ammonia(NH3) and nitrite(NO2). The basis we use to reliably judge these two substances in our freshwater tank are the test results from simple liquid-reagent test kits. These are crude by laboratory standards but are the minimum type of test that works well for fishkeeping. Any traces of ammonia or nitrite(NO2) can be considered to be a mini-spike. The transition point from mini-spiking to "being in a fish-in cycling situation" is when the water steadily shows a level of ammonia or nitrite that does not drop back down to zero. A level of 0.25ppm or higher for either poison can be the beginning of permanent gill and/or nerve damage and at this sort of marginal level is particularly insideous because the fish often don't show stress symptoms like at they do up at the 1ppm level, where you often see a reduction in normal movement patterns and often a loss of color and sometimes positioning at a different place in the tank from normal.
So unfortunately, observation of cloudiness being present or going away is a poor substitute for having a good liquid-reagent based test kit and being ready to use it more frequently for a spell when you suspect something might be wrong in your tank!
Neon tetras don't like to grab flake from the water surface. They are probably among the many mid-tank fish who feel extra stress when they get near the surface due to higher than normal vulnerability to predators above the surface as they evolved. They have colors more readily seen above the surface probably. It's always good to remember that different species feel different stresses related to surface or substrate, sheltered or unsheltered, based on the evolution of their species.
Anyway, in my opinion, the simple trick with neons and other mid-tetras is to gently grind the flake just below the water surface and slightly swirl your fingers so that you get a more widely distributed raining down of flake bits. This way the big eaters can't get to it all but the little tetras will have plenty to find and attack as the food goes down. If you have a planted tank, a little excess food is no problem as it just adds to the macronutrients (N and P) for the plants and your weekly substrate-clean-water-change should get rid of most of the excess.
~~waterdrop~~
