So I've been cycling fish fish food.. There has been a white mold growing on the food, I thought nothing of it. Asked a few people on here, no one knew.. I did some research, and it turns out that this mold can very possibly be the columnaris disease that you are feeding. A few fish forums said the mold usually dies down after a while. Mold is present in all tanks, and it could very well be harmless, but I am not willing to take a RISK with a fungus that could hurt fish growing in my tanks. Most of these water molds look the same, so there isn't really a way to tell what is growing right now. I am very dissapointed that this happened, I am sucking up the fish food.
The raw shrimp method is NOT a safe way to cycle your tank. I would highly recommend removing any dead shrimp you may have atm, even if no signs of mold are present.
The fish food cycling, you MUST liquefy the food, so the fungus has no base to grow on.
"The only risk of the fish food method is the possibility of Saprolegnia (mold) growing on rotting fish food which can become pathogenic to new fish that will be introduced later.
This is easily avoided with a fish flake food by powdering it between fingers before introduction to the aquarium (shaking fish flake food in a cup of water can also accomplish this). This risk is relatively small and basically non-existent when you use an easily “liquefied” fish flake food. This unfortunately is NOT the case with the raw shrimp method (recommended by a few poorly researched sites)."
"There are other methods of fishless cycling being recommended or used however one method being pushed on the internet by "cut & paste", anecdotal websites and forums is the use of Raw Shrimp; however this is a recycled idea (which included the use of silversides, frozen shrimp, and even dead feeder fish) and has reappeared on the internet even though it was debunked in the early 1990's!
I do not recommend this method, not because it does not work for cycling, but because it may also allow a Saprolegnia infection to get started in your new aquarium (or at the very least; heterotrophic bacteria which is not a desirable nitirfying bacteria as discussed earlier).
Saprolegnia is a mold (often called a fungus) that easily gets a foot hold in decaying nitrogenous matter such as raw shrimp and I have seen this many times in my experiments. Even after the source of Saprolegnia growth is removed, the secondary zoospores which are the primary mode of pathogenic transmission can remain, even after large water changes/vacuumings.
A new tank is the worst time to have a Saprolegnia infection get started as this is when fish are often much less resistant to disease due to the stressor of a new tank environment."
As for solving this problem, could treating the tank for fungus help?