Fishkeeping Mistakes You Might Be Making

Fishkeepers, both old and new, can always learn something new about keeping tropical fish. This is a hobby with endless amounts of information, so we understand you cannot retain it all! Nobody is perfect and all fishkeepers make mistakes, especially when they are first starting. We have compiled a list of the most common mistakes that hobbyists make and how to avoid them.

Overstocking/ adding too many new fish at one time

When your fish tank is all cycled and ready for livestock, it is very exciting to select what species you want in your tank. Some of us may get a little too excited and buy too many fish for your filter to handle at once. Adding too many fish at one time will cause a drastic increase in ammonia and nitrite in your tank and your filtration system will not be able to keep up. Overstocking can also lead to fish becoming stressed. A stressed fish will have a weak immune system, and the unbalanced water levels will lead to them becoming ill and dying. The amount of fish you can add depends on the species of fish and the size of fish tank you have.  

Cleaning filter foams in tap water

The beneficial bacteria that build up in the weeks of cycling your fish tank before adding fish will be completely washed away by rinsing your filter foams in tap water. It is essentially, re-starting your filter cycling process! This is harmful to your fish because the beneficial bacteria in the foams convert harmful wastes so that the fish stay alive and healthy. ALWAYS wash the filter foams in old tank water and make sure it is never exposed to soaps and other cleaning products.


Feeding your fish too much leads to increased health risks, and any food left in the tank will lead to rotting and an imbalance in your tank water.  Decaying food in your tank and increased waste produced by your fish after eating too much will increase harmful ammonia and contribute to cloudy water and reduced oxygen levels.

Overfeeding is common because it is so easy to do. Fish learn that you are their source of food, so when you approach your tank they may swim towards you and look at you with hungry eyes. Don’t let them trick you into feeding them, they are not starving. We recommend feeding your fish once per day and only feed them as much as they can consume in 3-5 minutes. Any food left over in your tank should be taken out. 

Not buying enough of a shoaling fish species

Many tropical fish species, like tetras, are sociable by nature. They thrive off of the other fish that surround them in the tank. Shoaling species have innate predispositions to form hierarchies, breeding pairs, etc. If there are not enough of the same species of fish in a shoal, they will become shy and hide away, and even start to be picked on by the other fish in the aquarium. Many shoaling species should be kept with at least 6 of their kind, but 10 is probably best.

Mixing incompatible fish

Putting incompatible fish in the same tank is a very common problem that leads to damaged health and death of a lot of fish. We at AllPondSolutions do everything we can to ensure that every customer that orders from us is informed of the compatibility of all the fish that they wish to purchase. We strongly encourage you to do research on each fish you want to buy before you place an order for aquarium livestock. There are so many beautiful tropical fish, and while you may want all the inhabitants of your tank to look a certain way, they could end up being seriously harmed. Different species have different water requirements, should not be mixed with fish that have certain fins or are very territorial and aggressive. So we cannot stress enough how important it is to learn about the fish species that you wish to own. 


You may think that under-cleaning is the major issue that leads to water instability, which in turn leads to problems within the aquarium. But, what you might not know is that over-cleaning can do just as much damage. After the many weeks of cycling your fish tank, good bacteria is established everywhere in the tank and filter. By cleaning everything at once (ornaments, glass, water change, filter media change, etc.) the bacterium that benefits your fish is depleted. This is why you should schedule cleaning in stages and stick to a maintenance schedule.

Lacking patience

Remember, this is a hobby that takes time and patience. It is a hobby that is meant to be relaxing, and even foster therapeutic effects. We know the feeling of wanting to get everything set-up and running smoothly as soon as possible, but taking your time will pay off in the long-run. Make sure you take the time to set-up your tank and filtration system properly, let your tank cycle for 6-8 weeks and do plenty of research on the fish species you are interested in keeping. You will end up with a smoother running fish tank and not as many unanticipated problems will occur.