如果發現培植土上出現白色點點，這是由水中有機物（魚屎或溶在水中的魚糧）的沉積引致，並不是發霉或產生細菌，對魚及植物也沒有害，因此培植土否繼續使用而不需更換，另一個情況，如果表面出現綠色團狀物，代表霉菌積聚，應立即解決。霉菌出現的主要成因是室內空氣不流通及濕度過高，特別是種植小麥草時，種子放得過於擠迫，而且種子互相覆蓋，便會導致霉菌的出現。一旦可用小刀把霉菌刮走，如果範圍大，可以用刀把培植土的表面一層片走，培植土可繼續使用。
If white spots are found on growing medium, this is caused by the deposition of organic matter in the water (fish feces or fish food dissolved in water), not mouldy or producing bacteria and not harmful to fish and plants, so the cultivation of soil will continue use without replacement, on the other hand, if green clumps is found, that is a sign of mould, should be resolved immediately. The main cause of mould is indoor air flow and humidity is too high, especially the seeds are being placed to crowded when planting wheat grass, very likely it is going to induce mould. Try to scrape the mould away with a small knife, or slice the surface layer off if the affected area is very large. Your growing medium is fit for use after the treatment.