MagpHlow for pH control
General properties.. how to use MagpHlow
Bulk bed density = 1.8 kg per litre
A low pH of approximately pH 5.7 can now be easily adjusted to give a pH close to pH 7.0 by employing a gravity flow bed of MagpHlow. In marine systems MagpHlow media is used to buffer systems to a pH close to 8.3 without any risk of over dosing or development of too high a pH.
Magphlow consist of small spheres (2.0 to 6mm) . The MagpHlow are used in the form of a contact bed or pressure sand filter through which the water passes. The MagpHlow dissolves slowly in response to acidity in the water, and during the process the pH and magnesium hardness of the water are increased.
At a pH of 8.3 MagpHlow is insoluble in the water, as the pH becomes more acidic, the solubility of MagpHlow media increases, the product therefore has a built in pH buffering capacity. Due to the pH increase on the Magphlow surface the product is also excellent for heavy metal reduction.
Magphlow can be held in either existing sand filters, pressure sand filters pressure AFM filters or gravity flow filters, they can even be spread in the vicinity of water intakes. In each of these situations the performance of the MagpHlow bed is literally automatic and no sophisticated pH metering equipment is required. All that is required is that the bed should be topped up with fresh MagpHlow every few weeks or months to replace the MagpHlow which have been used.
How much to use ?
The pH of the water is adjusted by varying the amount of MagpHlow in the filter. As an approximate guide, if it is desired to raise the pH from 5.5 to pH 6.8, approximately 0.25 to 0.75 kg of MagpHlow are required per cubic metre of water treated over a 24 hour period. For example if the water flow is 100 cubic metres per day the amount of MagpHlow required would range from 25 to 75kg.
The pH of water is a log scale, thus if it takes 300 kg to raise the pH of the water from 5.5 to 6.8, it could take 3,000 kg (ten times as much) to raise the pH to 7.8. It is virtually impossible to raise the pH of the water to levels greater than pH 8.3 since the magnesium will precipitate out of solution. This property also make Magphlow the ideal buffer to employ in marine hatcheries and recirculation systems.
In a marine system you can not use too much of the MagpHlow product, indeed the more you have in the system the more stable the pH. As a guide we would recommend 1 to 2 kg of media per cubic metre of water treated per day.
In situations where the freshwater water is recycled, the amount ofMagpHlow media should be equivalent to 0.25kg of media for every cubic metre of water recycled per hour. In a marine recycle system this figure should be closer to 0.5kg for every cubic meter of water recycled per hour. For example, in a marine system if the recycle flowrate was 50 cubic metres per hour, there should be at least 25 kg of MagpHlow media in the the recycled water.
The above figures should be used only as a guideline since there can be a wide variation in the actual quantity required in any given system. There is also a small quantity of sodium present in MagpHlow media which will result in an initial high pH. It is therefore important to Read this before using the product.
Heavy metal removal
On passage of water through a bed MagpHlow the pH of the water will be increased and the solubility of metals will be reduced. Some of the metals may form a precipitate that will be removed by the sand of AFMïfilter media in the pressure vessel.
The micro environment on the surface of the MagpHlow is pH 8.3. At this pH metals will have a tendency to form a precipitate on the surface of the Magphlow. The surface coating will eventually rMagpHlow along with the heavy metals will be removed. The surface cleaning works better when using AFM
The pH of freshwater is very important to the health and vitality of fish and aquatic life. The salmonids, including Atlantic salmon, and Rainbow trout, are especially sensitive to pH. The critical stage is during egg incubation, egg hatch and through to first feeding. These periods normally coincide with the winter and spring months which are also the months when a low pH and acidic water can be expected.
Recycle systems, in recirculation systems the activity of the biofilters and fish will decrease the pH of the water rendering it more acidic. It is important that the system is buffered against acidic conditions and fluctuating pH since both factors will destabilize the biofilters and stress the fish. In marine system this is very important, if the pH is allowed to fall below pH 7.8 it means that the carbonate buffering capacity of the water has been exceeded and that the system could pH bounce. It is essential that the pH is increased and maintained between pH 8.0 and 8.3, MagpHlow media has been used for over 10 years to achieve this task and has been proved to be the ideal process in both marine and freshwater systems.
Read this before using product
The MagpHlow contains some magnesium hydroxide dust, it is therefore important that the product is washed to remove the dust prior to it being added to the system. The MagpHlow media also contains a small amount of potassium and sodium hydroxide. These hydroxides will dissolve during the first 48 hours of use giving a high pH. The MagpHlow should therefore be soaked for 48 hours prior to use and then added in small portions over approximately 7 days until the desired pH is obtained. This policy will ensure the you do not stress the fish with a sudden pH shift, and that you obtain the pH desired.