November 21, 2022

Old Tank Syndrome

Old Tank Syndrome

High Waste Levels in an established aquarium

The condition sometimes referred to as "old tank syndrome" occurs in tanks which have one or more of the following:

  • Too few or too small partial water changes
  • Excessive dirt build-up, especially in the gravel
  • Too many fish (overstocked)
  • Too much food being added

Effects on water quality include very high nitrate levels, low pH levels, possibly low oxygen levels, and sometimes measurable levels of ammonia and/or nitrite.

These will cause fish to look less vibrant than they should, make them less likely to breed, more prone to disease, and shorten their lifespan (most fish should live several years).

The above symptoms may not be immediately obvious. Often the problem is only noticed when newly added fish die regularly. The long-term residents have had time to get used to the steadily increasing waste levels, but the high levels will be a shock to newly added fish.

Good tank maintenance, an appropriate stocking level for your tank size, and careful feeding can help prevent or remedy the above problems.

If you have any doubts about your water quality, we can test a sample of your tank water. Alternatively, we have simple-to-use test kits available, so that you can monitor your water quality regularly.