I have tried for quite some time and have finally come up with a method that can be implemented and will achieve the above thus saving hobbyists money when lowering silicates and phosphates in their aquariums. This method applies to all ores (metal oxides in this case) used to remove phosphate and or silicate.

After a lot of experimenting, and after talking to the manufacturers of the ore that is used in making these compounds, the following seems to be a viable solution that can be used to "partially" regenerate the compounds, thus extending their life.

Whereas full regeneration does not appear to be possible based on the consensus of those consulted, and experimenting with different regeneration methods, the method described here will allow hobbyists to at least double, if not triple, the life of the compounds by following the instructions given, carefully.

Note that this involves the use of a strong acid and that high caution is required when performing this procedure. Eye wear and gloves are strongly recommended. Note also that the acid used for this process should "definitely" be kept out of reach of children, and should be stored in an area that they have no access to.

This is a "real" caution and warning, as severe burns can ensue if the acid is spilled over hands or body parts, or gets into one's eyes, whether children or adults. Note too that the acid will cause damage to whatever it comes in contact with, whether it be clothes, carpet, floorboards, cabinets, in short anything. Be very careful not to spill the acid or even the diluted solution used to treat the compounds.

Below are the step to take to regenerate the compounds:

• Acquire a bottle of Muriatic Acid (itself a dilution of Hydrochloric acid). Even though this is a diluted acid, it is still very strong and can cause burns and damage to whatever it comes in contact with. Use caution when handling this liquid. Muriatic acid is sold in do-it-yourself stores and in swimming pool supply places.
• Prepare a dilution containing 5% muriatic acid and 95% water and do so in the following manner:
  • To 95 parts of water add 5 parts of the acid.
  • Do so by taking for example 95% water and 5% Muriatic acid.
  • Another way to look at this is to take 950 ml of water and 50 ml of the acid.
  • To do so you will need a measuring device that allows you to determine the exact quantities above. Use glass containers or use plastic ones that are rated as safe for use with acids. Most polyethylene or polypropylene ones are.
  • It is easier to work with liters in this case than with gallons as the amounts to be mixed are easier to determine.
  • The acid is added to the water not the opposite.
• Now that you have the diluted solution pour it gently through the compound.
• You can only pour the solution through the compound once. Whatever has gone through is collected in a vessel underneath the container, for later safe disposal
• Pour as much solution through as required for the amount of compound you are treating (see below).

If you cannot find equipment to measure in ml and/or liters, and you need to use gallons or quarts, remember that you need to use 95 parts of water and 5 parts of acid (for example 95 fluid ounces of water and 5 fluid ounces of Muriatic acid).

The best way to do this is to place the compound in a plastic acid safe container that is perforated at the bottom (a sieve). Place that sieve on top of a bucket for instance and pour the solution slowly and evenly over the compound. If will seep through, flow out through the sieve's holes and collect in the container underneath.

How much solution do you need: for every 10 ounces by weight you will need approximately one gallon of the solution (3.785 liters).

After you have poured the solution through the compound you will need to dispose of the diluted Muriatic acid in a safe manner. This is done by diluting it further so the acidity is neutralized before it is poured down a sink or a toilet. Neutralize the acid by diluting small amounts of it in water (for every liter use 10 liters of water).

Now you are left with your regenerated compound. Note that it is still full of acid and that you need to rinse it with treated water (e.g. R.O.) until all the acidity is removed. Keep pouring treated water through the compound until the pH of the effluent is around 7 to 7.5. It may take quite a bit of water to accomplish this. After the compound has been properly rinsed, let it dry by spreading it out in a thin layer. When it is dry it is ready to be used again.

You will probably find that the regeneration process makes you loose some of the material. Some of it will break up in small pieces and pass through the holes in the sieve. This is normal. On average, you will loose around 8%. This is an average so individual cases will vary. As you regenerate more than once, you may find that the compound will break up more and than on a second regeneration you will loose more of the compound than on the first one. I do not recommend regenerating more than two times.

The water in the vessel underneath the sieve will contain this broken up material (compound). This water, and what it contains, cannot be reused for anything. Some have suggested that such acidic water can be used in pools to lower the pH. This not the case. Dispose of the water in the manner indicated earlier. Besides being acidic the water is full of contaminants and needs to be sewered.