I linked this before, but I think it's important that the information gets out since this is a common misconception. Here's an excerpt from Oscarfish.com. It gives some information on the bacterial blooms cause, and ways to manage it.
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"Cloudy Water
Whenever you hear reference to a “bacteria bloom” resulting in cloudy water, it is the heterotrophic bacteria that are causing this bloom, not the nitrifying bacteria. Autotrophic nitrifying bacteria reproduce too slowly to cause cloudy water. Therefore, cloudy water from a bacterial bloom is not necessarily an indication of a cycling tank, a common reference that could only be correct if it is an indication that all bacteria in the tank has been wiped out (a result of medications, chlorination, etc…) or if it is a new tank void of heterotrophic bacteria. Regardless, in most cases associated with an established tank, cloudy water is an indication of excess organics, not a tank cycle.
While a tank cycle is not the cause of cloudy water, cloudy water could, however, result in tank mini-cycle. A bacterial bloom resulting in cloudy water is an indication of excess dissolved organics existing in the water column. A subsequent explosion of heterotrophic bacteria will occur to consume these organics, eventually converting them into ammonia. If the existing colonies of nitrifying bacteria are insufficient to deal with the sudden (but temporary) increase in ammonia, spikes will occur. In addition, since heterotrophic bacteria compete with autotrophic bacteria for oxygen and surface area, such an explosion of heterotrophic bacteria may reduce oxygen levels available to the autotrophic nitrifying bacteria, potentially making them less efficient and less able to compete. With the excess food source available to the heterotrophs, along with the reduction in oxygen, combined with the ability of heterotrophs to out-populate the autotrophs by a factor of 4,722,366,482,869,645,213,696 to 11 , the heterotrophs can quickly take over the available surface area. The potential end result, the heterotrophs over run the autotrophs, resulting in subsequent spikes in ammonia and/or nitrite, until the excess organics are consumed (or removed), at which point the autotrophs can start to regain ground.
As has been mentioned several times, you prevent this potential issue by providing an environment conducive to autotrophic nitrifying bacteria. With sufficient (excess) surface area, sufficient (excess) flow rates, sufficient (excess) oxygen levels, and an optimal temperature, an explosion of heterotrophic bacteria can occur without impacting the autotrophic bacteria. The heterotrophic bacteria population will expand, but with sufficient surface area and oxygen, they will not overrun the autotrophs and the colonies of nitrifying bacteria will be able to expand (provided an optimal temperature is maintained) to deal with the additional ammonia.
Should you face a bacterial bloom, one of the first actions that should be taken is to increase aeration by whatever means necessary. This should be done as much to protect your fish as it should be done to protect the autotrophic nitrifying bacteria. In sufficient quantities, heterotrophic bacteria can quickly consume all of the available oxygen, leaving none for the fish or the autotrophs. A bacterial bloom sufficient to cause cloudy water suggests that your tank is at risk of becoming depleted in oxygen."