Though it achieves efficient filtration capability, one of the disadvantages, is the high cost of running it. A regular pack of diatom filter can cost about $3 to $5 and the efficiency of the filter media can last the most about 2 days depending on how dirty and contaminated the aquarium water is. You can imagine how much would it cost just to leave it to run continuously without stopping and changing the filter earth about once every 2 days which would total up to about $45 to $75 per month. Therefore aquarist usually employ the use of diatom filter only when needed and it is most useful when it comes to removing aquarium medication from the water after treatment for sick fish has been completed.
Aquarium diatom filter works well both for freshwater and saltwater tank setup. However several precautions has to be put in place and remembered before you actually started using it. First as mentioned earlier, diatom filters are so efficient that sometimes even free-floating microorganisms like plankton which is actually food for your saltwater fish can get trapped and therefore it is not necessary to run it further once you achieved crystal clear water. Next, during the operation of the aquarium filter, frequently monitor the pH of your water. Based on my own experience, certain batch of diatomaceous earth can actually lower the pH and cause the water to become acidic. Although I still can’t exactly pinpoint whether it could be due to the filter media or it is just pure coincidence but it would be best to keep a vigilant watch during the filter operation.