Make your own free website on



"REEF CORNER" by Kirk Masters

Preservation and Quality Care of Our Reef Friends

You may see some advice that seems to be more than what our corals and rocks get in the ocean. What we are trying to recommend is called Primary Care or the best preventative care that you can give your new pets. If we wait for our corals to start to die first then we have not been proactive in providing the best care available. It is not costly to do so, but it is costly Not to do so. Most of us try to operate our cars at their maximum efficiency. We can do that in our tanks by setting up the chemistry very simply and effectively to maximize calcification and growth. Twenty years ago to keep these life forms alive was almost unheard of. Today, we can even propage, take cuttings and give small corals away to our friends.

Water for the Reef Aquarium:

Is any old water okay for a Reef tank? Can you use tap water? Yes, but lets look at what happens in a Reef tank. My 90 gal tank evaporates about 1 gal per day. I add Ultra-Kalkwasser (Calcium hydroxide powder) to this makeup water. The high pH of the water precipatates most of the heavy metals, iron, magnesium, some lead, copper and most importantly phosphate ( by forming Calcium Phosphate which is a solid material). We are left with a calcium hydroxide solution with silica and strontium hydroxide in it plus some nasties we don’t want in our water from pollution in the lake. We are lucky that the lake water is normally very low in nitrates (thank you algae and zebra mussels). Most of what is left is good for our use. If I add 1 gallon each day I concentrate the bad stuff by 400% over one year not accounting for some small monthly water changes. You can see that in a fresh water aquarium we can change 20% of the water per week and get rid of the concentrating effect that evaporation causes. Using Ultra-Kalkwasser helps a lot but doesn’t get rid of everything. (I will talk about Kalkwasser later). We are both lucky and unlucky. Today there is a simple solution and relatively low cost compared to only a few years ago. That is the use of a reverse osmosis membrane system. By using our tap water pressure it forces the water through a special thin film membrane (TFM) and gets rid of 98% everything good and bad. We can even go one step further and remove everything by adding a demineralizer unit after the RO unit. There are many different manufactures on the market. The best ones use TFM (thin film membranes). I use a DI unit for my tanks to get rid of all of the silica but you may not have to use one. One can always start a Reef without an RO unit and add one later like I did. Remember to use a TFM and not the cheaper cellulose units. SpectraPure has a very good name in the industry. Their DI units are suppose to have a much longer life than other units (500-600gal). If you use city water then all you need is a combination carbon and sediment filter in front of the TFM. This lowers your cost. If you have well water the iron could be a problem and a pre-filter is in order. The city filters our water and basically all we have to do is to remove the chlorine(carbon does this in the mixed filter). The sizes vary from 10 GPD to 50 GPD. If you keep the temperature about 85 F you can increase your throughput. I use a 35gpd because I don’t like to wait too long for my water. Many people are told that you can soften your water with peat or other chemicals. The truth is these things do not work. They do not remove the hardness ions (calcium and magnesium). Using a demineralizer without an RO would last about 5-10 gallons or so. RO units are used world wide to remove the salt from ocean water. If you remove the alkalinity with the use of an acid or the addition of a buffer, over a very short period of time the CO2 from the air changes to bicarbonate alkalinity and we return to where we started from. When I started to use RO water for my fresh water tank in Kitchener where the water is very hard, my plants started growing fantastically and the pH of my Angel fish tank dropped to around 7 or lower. My sword plants had over 60 leafs and looked great. Lighting was two small full spectrum standard watt actinic and daylight bulbs. (Tip: Use a new electronic ballast will greatly enhance bulb life, output will be maintained over a longer period. Hair algae was minimal. Water changes were about 20% per week RO water.

In a Reef we add light and other things to keep the corals and coralline algae growing. Those beautiful reds, purple, green and white rocks are covered with coralline algae. These are calcium based life forms and hence use a lot of calcium up. In an ocean we have a little life with lots of water. In our tanks we have lots of life and a little water. We must add:

1. Calcium
2. Alkalinity(also known as buffer or pH)
3. Trace elements
4. Food for the fish.
5. Food for some special corals.

That seems simple enough. We want to maintain a rather high pH of 8.4 (8.2-8.5 max.). This is easy to do. All we have to do is to add a level teaspoon of that Kalkwasser in a gallon of water, shake like heck and wait for it to settle for a couple of hours. It can then be dripped into the tank (using a pump or IV dripper line type of systems one drop at a time, all available locally). TOO fast a feed rate will kill everything if the pH gets too high. This is very good for hard stony corals, clams (those beautiful yellow, blue, brown tridacna clams not the ones you eat). A tridacna clam not only is a wonderful thing to have in a Reef (I have 2) but they help to lower ammonia and nitrate levels. If you remember we talked about the Berlin type system. That is live rock and a protein skimmer. A good protein skimmer aerates the water about 2 tank volumes per hour giving us excellent carbon dioxide balancing. The dissolved CO2 reacts with the calcium hydroxide to give us calcium bicarbonate or our alkalinity. What we end up doing is setting the conditions in the aquarium for optimum coral calcification (pH=8.4 or dKH = 15 degrees). Now what is that darn dKH? It is the way the Germans use to measure the alkalinity in water. It is called degrees German hardness like it because we can talk about small numbers 8 or 16 verse 137 or 274ppm bicarbonate alkalinity. I believe in KISS. Keep It Short and Simple. Testing therefore is one drop per 5mls gives 1 dKH. Do you need a pH meter at first? No. A pH meter is a great way to monitor your tank without lifting a finger or doing testing on a more frequent basis. Yes I use a pH meter and an ORP meter, but that is to get all of the information I can so that I can evaluate what is happening. Get a pH meter down the road, you will love it.

Understanding our water chemistry is all about understanding what happens to the dissolved carbon dioxide gas in water. The more CO2 we have as bicarbonate alkalinity the higher the pH. They (pH & alkalinity) are related in an open system but can have subtle changes in an aquarium. Bicarbonate alkalinity is the Bus that carries the calcium. For every calcium ion it has a spare seat.(also for strontium a similar metal ion to calcium). Along side of calcium is magnesium. In sea water magnesium concentration is 3.5 times that of calcium. It is because of magnesium the calcium ion concentration can reach over 550 PPM in a Reef tank (control above 425 PPM). Think of magnesium as one of the driving wheels on the BUS. Like a busy city, there are about 4 times as many people waiting for a seat on the bus as there are seats. The remaining calcium (waiting for a seat) is in the form of chlorides and sulfates.

Sea water can be divided into major, minor and trace elements according to the level of the elements dissolved in it. The major elements are sodium chloride (35,000 PPM), magnesium (1450 PPM), calcium (425 PPM), potassium (400 PPM), sulphates. Nothing could be easier to keep our salt at the right level. We use a simple hygrometer that floats a needle pointing to the specific gravity. Same idea as testing our battery or water in our radiator or making wine.

The minor elements are strontium (8 PPM). Too difficult to test for now. Just add regularly is good enough.

The trace elements are the rest. We need these to live also. Some we need some we don’t. Iodide and iron are the most important of the trace elements and need to be replenished as protein skimming and activated carbon tend to lower their concentration. We simply add a trace element mixture like Ultra-Elements every week or two and that is it. It is always best to start very slowing when adding trace elements and use half of what a manufacturer recommends because the iron can cause hair algae to grow. Ultra-Elements is also good Using things like ozone because it will removed trace elements(not really needed in a reef). I will talk about ozone in another issue. I will also cover food for a Reef, lighting, etc. in following issues. Remember to e-mail or send in your questions. We will publish your questions and answers. Happy Reefing. Once you get going you will love it!


Electronic mail
General Information:

Hit Counter