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8.6 COPPER:

No copper whatsoever, except for traces that are part of the salt used, should ever be present in a reef aquarium. Copper is very toxic to corals and invertebrates and will cause them to die, or never open to their fullest. You can, therefore, not treat reef tanks with any medication containing copper, even when parasitic disease is present in your tank. You must treat disease differently.

Where does the copper that some hobbyists find in their tanks come from? We have already pointed to copper pipe as part of a house, or building's water supply system, as one source. Other sources include rock that has been used in another tank in which copper based medication had been used. If the rock you want to place in the tank appears to have been used before, do not add it to a reef tank. You must first examine it to make sure it does not contain any precipitated copper.

To do so, place the rock in copper free fresh water. Lower the pH of that water by adding some acid to it, e.g. a little muriatic acid found at many hardware stores. Let the rock sit in that solution for 12-24 hours. Move it around forcefully in the water from time to time. After 12-24 hours perform a copper test on the water. If copper is present it obviously came out of the rock(s). Don't use it in your reef aquarium.

Lava rock, especially the reddish variety, is inexpensive. As a result many hobbyists want to use it as the base on which they will place other rocks, rocks that have lifeforms on them. Because you do not know where such rock actually came from, and because you do not know either what it will leach into your water, I strongly recommend against the use of such rock in reef aquariums. Stick with lime based rock.

Alternatively, soak some pieces of rock in 5 gallons of acidified water for several days and test for leachings of heavy metals such as copper and zinc, sulfur and so on. If none are present, go to the next step.

Now prepare the water in which you had the rock, the 5 gallons, and add salt to it, as if you were going to add it to your tank. Do not add it to your tank however. Transfer it into a 5 gallon aquarium. Adjust the pH and temperature if necessary. Now add a small anemone to that tank and see what happens to it over the course of a few days. If it dies, seems to close up completely, and generally does not look good, chances are the rock has leached compounds in the water that you do not want in your reef tank. If it does all right, the rock is probably all right to use as well and may be placed in your reef aquarium.

As a last remark: Once you have determined that no copper is present in your reef aquarium, test for copper on an infrequent basis anyway, maybe once a month, just to be sure that it has not suddenly appeared, even in low levels, and is building up to amounts that could become toxic if not removed.

Copper can be removed from your system by performing water changes with copper free water, or by using Poly Filters from Poly Bio Marine Inc. Do not resort to using chemicals. All such chemicals do is precipitate the copper out of solution. This does not remove it from your tank, and the copper may go back into solution later on. If you use Poly Filters in your system, you should not have to worry about copper building up, as they are very efficient at removing it.

8.7 CARBONATE HARDNESS, KH LEVEL:

You must test the KH level of your tank frequently. I recommend you do so at least once a week. Twice is better. Keep records too. Use the sheet shown on page 194, or something similar. Keep the KH level between 12 and 18 dKH, 15 is the recommended level (Thiel, 1985). Some authors recommend even higher levels, for instance Peter Wilkens often suggests as much as 18-22 dKH.

Adjust the KH level whenever it has fallen from the previous reading that you obtained while testing. Use a KH generating compound that conforms to the characteristics I described earlier in the book. Keep the KH level up especially if you are using carbon dioxide to prevent acid fall. When the KH is low, and when you add CO2 the pH can drop quite rapidly. Do not let it happen. Check the KH level regularly and adjust it whenever necessary.

Besides adding KH generating fluids or powders, also add Kalkwasser on a regular basis. Daily is best. Kalkwasser affects the KH level too, as it adds calcium carbonate to the water. Calcium carbonate is required by all your hard corals. When raising the KH you can, and should, in my opinion, use a combination of KH generator and Kalkwasser. If you don't, you will find it difficult to add limewater once the KH is at the desired level, since Kalkwasser also raises the KH somewhat. I use equal amounts of each.

Never increase the KH level rapidly. As with any changes made to a reef aquarium, go slowly. If you test regularly, and if you adjust each time you test and an adjustment is necessary, the change and the amount required to adjust the KH level should not be large anyway. The carbonate hardness does go down, but it does not fall rapidly.

Sodium bicarbonate, better known as baking soda, will raise the KH level quickly. Do not use it. It will affect the pH a little downwards at first, and then it will gradually build it up to around 8.5 or 8.6. Because of the chemical nature of sodium bicarbonate you will have a hard time bringing the pH back down.

Besides, baking soda contains only one of the four or five (better) compounds that a good carbonate hardness generator should contain. It may sound like a good product to use because it is inexpensive and fast, but it is not. You are looking for problems especially if you use too much of it. At worst use it in an emergency situation, but not continuously. Too many hobbyists have had problems with too high pH levels as a result of overdosing. Some have reported a calcium fallout, a situation where calcium comes out of solution, and coats everything in the tank, including the glass and pipes.

Unfortunately too many hobbyists still use it, and in too large a quantity. Hopefully you will not be one of them.

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