Sulphur Nitrate NO₃ Filter

Suitable for freshwater and saltwater aquariums up to 400 - 600 litres

Installation

Hang the Sulphur Nitrate N0₃ filter vertically or stand within a sump.  The NO₃ Filter can only operate in an upright position.  The water input should be connected through the Micro filter into the adjustable flow-rate valve (tap).  Ingoing water must pass through the Micro filter first, to ensure the unit works efficiently.

Commissioning

Flush through with water before use to remove all dust particles, then discard this water.  Either connect the NO₃ Filter to the output of a sump pump by means of a bypass or gravity feed from the main aquarium, into the sump, at all times ensuring that the syphon can be broken should the return flow stop from the sump.  The flow through the NO₃ filter should be controlled by the tap.  It is always preferable to use the tap as the inflow to the filter.  The NO₃ filter water can drip directly into the aquarium or the sump according to the installation.

Settings

Regulate the flow rate at the outlet to one drop per second or lower if possible, but not less then one drop every two seconds.  Measure the N0₃ concentration at the outlet after four days.  If this has not dropped to 0 mg/litre wait until it has done so.  This can take up to 8-10 days when the temperature is near 16°C and if the N0₃ concentration is below 25 mg/litre.  

Once you have a null reading for over two days, you can increase the drip rate to two drops per second.  Wait again for a null reading for a further two continuous days and then increase the drip rate to four drops per second.  As soon as you have another two clear days of  NO₃, increase to 6 litres per hour. 

After a further two days of observing null mg NO₃, the rate can be increased to in excess of 7 litres per hour.  Finally, it is possible to increase the rate to 10 litres per hour, however you should wait for four days with null readings before doing so.  The filter is now commissioned.

Information

It is achievable under the right conditions to further increase the performance of the Nitrate NO₃ filter up to a maximum output of 15 litres per hour when there is a high concentration of  N0₃ in the water, however you should be aware that the pH returning from the Nitrate filter will be very low, and for small tanks it is better to run it slowly.  The Nitrate levels will fall but it will take a little longer and will require less buffering.

Buffering: The water leaving the NO₃ filter has a very low pH, approximately 6 to 6.5 or lower in fresh water.  This water can be dripped over coral sand to raise the pH before entering the aquarium, and / or through a container with an airstone in it.  This is particularly important on fresh water as coral sand should harden the water.

If you exceed at any time the maximum flow rate the system will break down and you must start again with the above starting procedure.

It is important to regularly flush the Micro filter through with vinegar to maintain constant flow. 

NOTE

The N0₃ filter will create a high NO₂ value for the first few days of any adjustment but will soon disappear to zero when commissioned correctly.  The unit only works at temperatures above 17°C.

The unit is connected to the cold water mains supply (tap connectors are not supplied as tap fitting vary considerably) and the flow is adjusted to approximately 25 gph (full tap flow is about 200 gph).  Allow about 5 gallons to waste

Collect required amount of water in a suitable container. Amount of water produced before unit is exhausted depends on the level of Nitrate/Phosphate in the water supply. Average is 30 - 70 gallons

The unit can be recharged using dishwasher salt (1 lb per gallon of water) and flushing this through the unit very slowly (about an hour). The unit should then be flushed with 3-5 gallons of fresh tap water before the unit is ready for use again.

Good quality Nitrate/Phosphate test kits should be used to monitor the output from the unit.