Henry & Tammy's Place/Water Quality

Maintaining Good Water Quality

Performing regular partial water changes
How often you choose to perform partial water changes should depend on the size of tank and the purpose for which the tank is being used. Most home aquarists would advise doing weekly water changes of approximately 20% to maintain your tanks. I believe it depends on the circumstances surrounding the particular tank. In our case, tanks smaller than 10 gallons may get water changes 3 times a week. Weekly water changes on 10 gallon tanks under normal conditions. Biweekly on tanks larger than that. In saying that, situations arise that may alter the best laid plans. So don't base what you do on my schedule. ALOT of what I do and when I do it may depend on what results I get when performing different water tests.
Regular gravel cleaning
Syphoning the gravel on the bottom of the tank is important to help reduce the amount of decaying uneaten food and removal of fish waste. Some folks will tell you that you should not replace the filter cartridges on the same day you syphon the gravel. This may be true in smaller tanks, but I've had no problems doing this on our larger tanks.
Not overstocking the tank
There are differing opinions on knowing when enough is enough when stocking tanks with fish. The general rule I see mentioned most is that it is safe if you have one inch of fish per gallon of water. I disagree with this rule. Far to often people don't prepare for the future needs of the fish. A one inch fish may grow significantly larger. If you don't intend on upgrading tanks to suit the fish as it grows and as its needs change you are inviting problems.
- Different fish excrete more waste than others. So whether or not there is adequate filtration to maintain the bioload.
- When adding fish to an aquarium what needs to be taken into consideration is the potential size of all the fish in the tank when they are fully mature.
- The ease with which the fish may spawn and whether or not you are prepared for a population explosion.
Not overfeeding the fish
Again, the rule of thumb here is not to feed your fish more than they can consume in a 5 minute period. This is a good rule! I'd also add that stocking your tank with a team of Bottom Feeders to help munch up any food that does reach the bottom is a good idea. So, you do need to make sure they get an adequate amount of food as well. Allowing your fish to fast one day a week isn't such a bad thing either.
Adequate levels of dissolved oxygen
Fish can not survive in water without oxygen. It seems to be the one area of maintaining a healthy aquarium that people overlook most often when problems arise and when considering the quality of water. It also is probably the easiest condition to control through aerating the water in the tank. Good aeration is vital to a fish tank. With the use of air pumps and air stones or with sufficient surface water agitation it is easy to achieve. Good aeration means a strong flow of air bubbles rising and bursting on the surface of the water. Also, the warmer water becomes, the less dissolved oxygen it holds. This should be kept in mind when regulating the temperature in our fish tanks. Just remember that low levels of oxygen can cause stress which can lead to all kinds of health problems for the fish. Recommended *minimum* dissolved oxygen levels for fish are:
- Warm water fish - 5.0 mg/L (ppm)
- Cold water fish - 6.0 mg/L (ppm)
- Koi - 8.0 mg/L (ppm)
- Marine fish - 5.0 mg/L (ppm)
Controlling levels of Carbon Dioxide
Carbon dioxide (CO2) is present in water in the form of a dissolved gas and forms carbonic acid and can lower pH. With decaying organic waste present in the aquarium the carbon dioxide concentration rises while the dissolved oxygen content falls. Plants in our aquariums do rely upon carbon dioxide and bicarbonates in water to grow but when the levels of carbon dioxide rise and the levels of dissolved oxygen fall the fish are left to compete with plants for the limited supply of dissolved oxygen which is present. The acceptable range of carbon dioxide for most fish is 2.0 mg/L (ppm).
Periodic testing of the water parameters and the importance of test kits
Fish produce waste and along with other organic components over time the water will change its composition. There never should be a time where a fishkeeper should become complacent to where they forego keeping tabs on the parameters of their water. There is always a series of events occuring in your aquarium that you can not see that may be having an adverse affect on your fish. Depending on whether or not your tank is fully cycled, different tests should be performed on a regular basis. Testing should be more frequent during the period while the nitrogen cycle is taking place in an aquarium. It is important to closely monitor the ammonia and nitrite during the intial stages of a cycle to protect the health of the fish.
The reasons we test these parameters are:
- Ammonia introduced by fish waste and decomposing organic debris, is the most toxic nitrogen compound. It is present in two forms. Free ammonia (NH3) and ionized ammonia (NH4+). Free ammonia is the most toxic of the two and will cause death in very low concentrations. The concentration of each form is pH and temperature dependent. The higher the pH and the temperature the the more toxic the ammonia. Once the nitrogen cycle is complete and with a properly functioning biological filter, the ammonia readings should remain at zero.
- Nitrite is less toxic than ammonia, but still very toxic as it inhibits the ability of the blood to carry oxygen and with levels exceeding .55ppm a condition called "brown blood disease" can occur which is always fatal. Nitrite is oxidized into nitrate by nitrobacteria bacteria present in the tank. As with ammonia, once the nitrogen cycle is complete and with a properly functioning biological filter, the nitrite readings should remain at zero.
- Nitrate is the end product of the nitrifying phase of the nitrogen cycle. It is much less toxic than either ammonia or nitrite. However, excessively high nitrates in the water is often used as an indicator of poor water quality and over an extended period of time can be harmful to the fish. Levels exceeding 50ppm are considered unhealthy for fish. Nitrate can be absorbed by plants and is reduced into free nitrogen by anaerobic bacteria living in the bottom substrate. An aquarium that does not have live plants in it will not have any anaerobic bacteria present, so nitrates will accumulate in the aquarium and need to be controlled by performing regular partial water changes.
- pH indicates the ratio of hydrogen ions to hydroxyl ions on a logarithmic scale from 0 (pure acid) to 14 (pure alkaline). Fish can tolerate a wide range, but cannot tolerate a rapid change. If you need to alter your pH you must do it slowly over time. Fish maintain a certain level of pH in their bloodstream and altering the level of pH in the tank rapidly can throw the fish into shock. Only under emergency circumstances should a rapid change be attempted and you should be aware of the risks of doing this. In saying that, it's best to try and not have to alter your pH but rather to choose fish that closely match the level of pH of your water source. Or find a way to naturally raise or lower the pH. As stated above, pH affects the free ammonia/ionized ammonia composition. Algae and live plants in a fish tank can drastically change an aquariums pH from night to day as well, due to a change in the amount of dissolved oxygen affecting the carbon dioxide present in the water.
These are the water parameters that will make or break a fish tank and you should have test kits available for at all times.

The Effects Of Poor Water Quality On Your Fish
We have all heard of the term cause and effect . That term can have no truer significance than when we are talking about what it means to the fish we confine in these enclosed environments! Depending on how committed we are to caring for our fish, our fish will either have long satisfying lives, or rather short periods of existence. By doing our utmost to maintain a healthy aquarium, the cause and effect can either be rewarding for the fish and the fishkeeper, or aggravating for the fishkeeper and devastating to the fish. I am not going to go into a big lecture on the duties of fishkeeping. I hope I've made it clear throughout this site the importance of caring for your fish in the proper manner. Bottom line is, if you are going to keep fish, take care of them and their environment. If you can't commit to doing so, then fish keeping is not for you. (Small lecture over)
Allowing the conditions in our tanks to deteriorate tend to have a snowballing effect. Poor water quality in a fish tank can effect one fish or all fish. Important signs to watch for include:
Behavioral changes in your fish
Fish who are gasping at the surface
Fish who appear sluggish, or resting on the bottom
Fish who lose their appetite
These characteristics are what you would see in the early stages of what I would call "toxic conditions". If allowed to continue, you would start seeing more visible signs/symptoms such as:
Clamped fins
Finrot
PopEye
Swollen and/or discoloration in their gills
Redness or streaks of blood at the base of their fins or flowing through their fins
It only goes down hill from here. I apologize if this section ends on a sour note. This was a subject too important to not discuss in all honesty.