Small Reef Aquarium Basics Book 6
Albert J. Thiel


2. Water Sources, Uses and Treatment


Up to this point, we have spent the greater part of this book talking about how to maintain the water quality necessary to keep invertebrates, corals, fish and other lifeforms normally added to Reef Tanks, in much better than average shape and condition. We have not said a word yet about the water itself and its sources, before it is added to the tank. Neither have we said anything about how water can, or should, be treated before it is used for the marine and reef aquarium.

Besides using it to fill their tanks, Hobbyists use water for the following three main purposes :

- to add water, when water changes are made,
- to regularly replenish evaporated water,
- when diluting water additives e.g. carbonate hardness liquids, trace elements, kalkwasser (limewater) vitamins, etc.

Whatever its purpose, the water used should be of superior qual- ity. What the latter means, and I have not seen it defined frequent- ly, is that all toxic and all unwanted matter, compounds, elements, or whatever they may be called, should have been removed through some process or another, prior to the water being used. In most cases it is the Hobbyist who decides which cleaning process will be used. I say in most cases, because a number of Hobbyists do not cleanse the water themselves, rather they buy water that has already been treated (e.g. distilled, or purified as it is now called by the USP) either from a Pet Store, or from some other supplier.

It is important to understand that "ensuring that the water used is of good quality", is a most consequential part of good tank maintenance. Indeed, once the water is in the tank, Hobbyists spend un- told hours, and money, trying to ensure that it remains of good quality. Adding bad, or inferior, quality water to begin with, does, therefore, not make sense at all, especially when you consider the efforts and money spent to upgrade, and maintain, the quality of the water once the tank is up and running, and contains a lot of expensive and precarious livestock to boot.

As we shall see later in this chapter, there are many ways to purify, cleanse, or simply said "clean up" water before it is added to the Reef, or fish tank. More important than which exact form of purifi- cation is used, is the fact that some form "is". And let me say right away that you do not have to get extremely fancy either, to get good water quality. There are many ways to do so that are both inex- pensive, and efficient, in terms of the effluent water produced.

Water Sources

Freshwater sources are the most commonly used ones for the purposes already mentioned, and include the following:

- tap water
- well water
- lake water
- river water
- distilled or purified bottled water
- mineral water (bottled)
- spring water (bottled)
- de-ionized water from outside vendors (bottles, bags)
- reverse osmosis water from outside vendors
- some even use or have access to lab quality water.

Purified seawater sources are not as frequently used, but are available in certain parts of the country. This is, of course, an excellent supply source, and its use should be encouraged. Unfortunately not many Hobbyists are lucky enough to have it available. If you do, consider using it on a regular basis, or from time to time. You may, for example, not wish to use it to perform all water changes, but you could, to keep costs down, use it every other time, or every third (etc.) time. Because of its "completeness" it is hard to beat its quality.

Water Uses

Top-Offs :

Replenishing evaporated water with cleansed "freshwater" is a task no Hobbyist can avoid, as no one has control over evaporation. Drip systems that operate on the "water level in the sump basis" are simple to install, and should be used if at all possible. They are very inexpensive and can be easily home made .

The diagram at the top of this page shows such a system.

Note the following about its operation :

- the freshwater bottle, or canister, must be "airtight". This is most important, as if it is not, the bottle will empty itself in a matter of minutes or even less.
- the principle behind this system is the same as the well known water dispenser in offices, where a large, usually 5 gallon, bottle sits upside down in the dispenser. As you push the manifold, water comes out of the spout. As the level inside the dispenser becomes lower than the bottom of the neck of the upside down bottle, air gets in the bottle, and water comes out, until the end of the neck of the bottle touches the water again. You can notice this happening when air suddenly rushes in the upside down bottle (while water gets out at the same time, and refills the reserve container inside the water dispenser).
- in this system the principle is exactly the same. As the end of the small internal diameter tubing is less immersed, because of evaporation, it will eventually be slightly out of the water. This lets air in, and water out of the reserve container, and achieves the desired result of adding water to the sump.
- the container, or bottle, must be rigid, so it will not crush as the vacuum inside of it becomes greater as it empties itself. Rigidness is most important, or your system will not work. If the container collapses on itself, all water will come out and be added to the system. Not what you are trying to do.
- use small internal diameter hose : 1/4 to 3/8 inch will work fine. Smaller may not work in all cases (especially if the run is long, and the container small). Rigid hose, or small diameter pipe will work even better. I use 3/8 internal diameter pvc pipe.
- Attach the bottle or canister with some sort of bracket, so it can not move up or down.
- Replenish the bottle whenever required. The larger the bottle or container is to begin with, the less often you will have to do so.

Alternatively you can, of course, as many Hobbyists do, perform the top-offs manually, adding the necessary amount of replacement water by hand. Make some sort of a mark on the side of the trickle filter sump, so you know where the level should be, and when it is not, add the required amount of "treated" water . Adding raw water, for example from the tap, can be done, but only if you are sure that that water is safe to use on your tank. This can only be determined by testing it extensively, something the average Hobbyist cannot do, or normally does not do.

To play it safe, treat the water by running it through some form of chemical filtration medium. I recommend Poly Filters (from Poly Bio Marine, or molecular absorption discs from the same company highly, and use them myself all the time.

Certain manufacturers sell small dosing pumps that will add water drop-wise to your tank. Two such companies are Tunze and my own. A small dosing pump to add drops should not cost you more than $160.00. The device can also be used, of course, for adding certain additives at the same time. Not all types of pumps can handle all types of additives (e.g. compounds that contain particulates can not be dispensed with small diameter peristaltic pumps, as the tubing would soon lose its vacuum, making the pump inoperative).

I also use a pump to add "Kalkwasser", meaning limewater, drop-wise to the Reef, to maintain a high calcium hardness (not the same as carbonate hardness). This greatly benefits my corals and also results in red, pink, purple and greyish coralline algae growing all over the aquarium. This a diaphragm type pump, not a peristaltic one.

If the doser pump (often a small peristaltic pump) that you use delivers more than the amount of water that you want to add to your tank, all you need to do is to run it for a lesser number of hours (not 24 hours, round the clock). Do so by using a timer. Radio Shack sells really excellent Micronta brand timers that are inexpensive, and will do the job just fine.

It is also recommended to place a small airstone in the container that holds the water from which the doser is pumping, and run a small amount of air through it. This is especially handy if you dispense a mixture of compounds, as i t will keep all parts in solution, and prevent the heavier ones from settling to the bottom (for example, calcium, vitamins, and some fertilizers).

If yours is the physical manual system of topping off, add the water slowly, and preferably to the sump of the trickle filter, not to the tank itself. It will mix better in that fashion. Top-off frequently, perhaps every day or every other day, if necessary.

Back to Table of ContentsBack One Chapter Top Next Page

netpets logo
NetPets® Main Page
contact information

Main Reference Library

The Fish Center