Case Study: NoPhos and algae control

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nophos case study 1

Algae and bacteria require phosphate as a micronutrient, remove the phosphate and it becomes very difficult for algae and bacterium to survive.

Most algaecides are toxic, such as quaternary ammonium chemicals and copper based products. NoPhos is not an algaecide; it does not work by killing the algae. Instead NoPhos removes the phosphate from the water, and slowly the algae and even bacterium starve and will s to lowly disappear.  The process is not quick, depending upon water temperature; it will take at least 6 weeks.  However it is a solution to the problem as opposed to a toxic camouflage provided by algaecides.

When an algaecide such as a copper based product is used, the copper will kill the algae.  The algae cell walls will leek and release organic phosphate as well as other nutrients back into the water.  After a few days, the copper will be chelated, oxides will form and the copper will precipitate out of solution. As the copper concentration drops, algae and bacteria will start to grow again.  Bacteria grow much quicker than algae, so an algae problem is temporarily solved by using toxic chemicals which results in a bacterium bloom that could be more pathogenic.  The use of algaecide is not environmental or functionally sensible, nor is it safe, a much better solution is NoPhos.

NoPhos will remove phosphate from the water; 10ml of NoPhos will remove 1g of phosphate.  If you have a water feature with 50m3 of water at a concentration of 0.4mg/l of phosphate, this equates with 50,000 x 0.4 =20,000mg or 20g of phosphate.  In order to remove the phosphate from the water add 20 x 10ml = 200ml of NoPhos.

nophos 5kg kl

NoPhos will remove all of the dissolved phosphate from solution, but as algae and bacteria die, they release their contents including organic phosphate back into the water.  It is therefore important that there is always some NoPhos in solution in order to grab this phosphate to prevent it from being used to grow more bacteria and algae.  The life span of algae is around 6 weeks, so you need to keep adding manually small amounts of NoPhos every weekor continuously using a small peristaltic doing pump.  Gradually the algae will disappear and you will be left with clean clear water.

A small amount of phosphate will continue to be introduced to the water from birds, or from leaves or other plant material entering the system. NoPhos addition should continue at a low level that maintains zero (<0.05mg/l) phosphate is solution.  In addition to NoPhos, simple phosphate test kits are available from Dryden Aqua that permits detection of low concentrations of phosphate.

There is a Legionella risk from biofilm in fountains or any water feature that generates an aerosol.  DryOx chlorine dioxide is very effective cleaning agent that removes biofilm to reduce the Legionella risk.  NoPhos then prevents the biofilm and algae from returning. 

Excellent results for AFM® in comparison with quartz sand and other glass filter media

IFTS Particle size removal performanceThe Dryden Aqua Team is proud to share with you the excellent outcome of the tests on AFM® in comparison with quartz sand and other glass filter media that were conducted by the “Institut de la Filtration et des Techniques Séparatives” IFTS in France.

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Dryden Aqua founder Dr Howard Dryden explains what drove him to look for alternatives to traditional sand in pool filtration

Howard Dryden Portrait

The heart of any swimming-pool water-treatment system is the sand in the sand filter. However, like any heart it does not work well unless it has a good support structure and circulatory system. The performance of the water-treatment system in a pool depends on the quality of the sand – yet there is huge variation in sand quality from different suppliers and quarries. The best sand in the UK is considered to be the Leighton Buzzard deposit.