Perpetual Preservation SystemTM

The most accurate Aquatic plant fertilizers


Water Changes

There are several reasons why people do water changes. One is in fish only aquariums to remove excess fish waste. Next is in poorly planted aquariums with too many fish for the same reasons as fish only aquariums. Next is in fully planted aquariums with reasonable fish load and with poorly designed fertilizers causing unbalanced remains of chemicals. The last is in fully planted aquariums with leaking substances as decorations, rocks or substrates. Other then that, there is no reason for extra water changes in properly designed, maintained and fertilized aquariums.


Can water changes be overdone and harmful?
That depends on the water source. If you use clean tap water or RO water then there is generally no harm, but some tap waters contain damaging chemicals. Some tap water sources will wipe out everything alive.
Also, there are reports of increased plant, fish and algae issues linked to water changes, regardless of the fertilization method. This has been reported by new and advanced aquascapers. More water they change more issues they get. Interestingly, it can be tap or RO Reverse Osmosis water, no difference. Why? Nobody knows yet.

If water changes are the key for success then why automatic constant fertilizer injected water flow systems don’t usually work?

Will aquarium water deteriorate without massive water changes in the long run?
Not necessarily. It depends on the aquarium setup. Well run fully planted aquariums with reasonable fish load can go without water change for years without any water quality deterioration. In contrary the older water can be cleaner and better then fresh tap water. How? By plant uptake. Plants have the ability to consume everything available cleaning the water in the process. Any chemicals, waste and toxins are mineralized by microorganism and become available to plants. Plants take these chemicals and store them in their plant tissue. Then when we trim the plants we are removing the toxins and chemicals out of the aquarium. Plants are the ultimate filters.

How do I know if I need a water change?
The first is to find the weakest point for that particular aquarium. It may be your NO3, PO4, KH, GH, Ca, TE trace elements or TDS conductivity. These are the most common issues and are described in the problems section. When you find the one element that causes the problem in your aquarium you know how to regulate it and keep it under control in the long run. This process may dictate the minimum rate of water changes.

Do I need to be testing all of the variables to determine the water changes?
No. Once you locate the most significant deteriorating factor the rest will be under control. For example, if you use KH leaking substrate you know by testing it that your aquarium may need 10% water change a week to keep it under control.