Spirex Aquatec Ltd

Bradley Green Redditch Worcestershire, B96 6TN, United Kingdom, +44 (0) 1527 821 601, info@spirexaquatec.com

Pond Healer Remedies


02:41 20-Oct-2017

Natural ponds and lakes can be subject to biological imbalance, leading to problems with water quality.
We have solutions to these problems:

 prolific growth of algae
 prolific growth of water weeds
 fertiliser-rich agricultural run-off
 fish food and angler's baits
 droppings from waterfowl, for example, geese
 dead leaves
 effluent from septic tank soakaways


Algal blooms and oxygen

The algal blooms that result from high levels of nutrients lead to unstable water quality. Green plants in the presence of sunlight produce oxygen and consume carbon dioxide by the process of photosynthesis. At high temperatures and in bright sunlight, algal blooms generate so much oxygen that the water becomes 'supersaturated' (more than 100% saturated). This excess oxygen can forms bubbles in the bodies of fish, and can kill fry, damage the fins of larger fish, and put them off feeding.
It follows that photosynthesis occurs during the hours of daylight, and 'switches off' at night. However, algae and other aquatic plants respire at all times, when they consume oxygen and generate carbon dioxide. Overnight, the surplus of oxygen is used up, and the large biomass present can then reduce oxygen to levels below that useable by fish (approximately 2mg/litre for coarse fish), when they begin to die.

Lakes depend on the atmosphere for a supply of oxygen through the water surface. Therefore, the capacity of a lake to absorb oxygen is limited by its surface area. Aerators significantly increase the surface area of the water, and therefore increase the exchange of gases (oxygen in, carbon dioxide out) with the atmosphere. This opposes growth of plants and algae, and increase the safe fish holding capacity of the lake.

Holistic Water Management

Given this background, it is plain that many factors influence water quality. We have a range of highly effective products that enable you to not simply control the symptoms of water quality problems, but attack the underlying causes.

 SD1 Sludge Digester
 Duckweed Control



What does it do ?


excalibarblocks the growth of most species of algaeenvironment-friendly, harmless to fish, invertebrates and wildlife
 'green-water' algae
blue-green algae
filamentous algae ('blanket weed')
swarm live, active, nutrient-scavenging bacteria, supplied in vast numbers, as 'instant dominant species'. Competes with algae, and other plant life, for nutrients environment-friendly, grows unobtrusively in the background, does not have a great oxygen demand, certified free of pathogenic bacteria.  Custom-produced, with minimum order quantities
clearfastclears suspended particles (including algae), usually within hours, by flocculationenvironment-friendly, chemically neutral, works by 'sticking' particles together by their electrical charges. Settling at the lake bed algae die

black mud, dead leaves and plant material, fish, bird and animal droppings
SD1 sludge digestersignificantly increases the rate of decomposition of organic matter at temperatures above 10°Cenvironment-friendly, extremely vigorous (consult supplier for applications above 20°C due to risk of de-oxygenation) Dissolves organic mud deposits, reduces nutrient reservoir in lake bed deposits, increases dissolved nutrients, for rainfall to dilute out of the lake. This reduces an underlying cause of water quality problems. In combination with Microchalk, can avoid the need for expensive dredging. Certified free of pathogenic bacteria
Microchalkneutralises acids in lake bed deposits, switching decomposition to faster aerobic pathway, mineralising organic matter. Replenishes carbonate where needed, 'kick-starting' the nitrogen cycle. Reverses stagnation.environment-friendly, reliable 'antidote' to stagnant, black pools, bringing them back to life. Can achieve spectacular reduction in organic mud depth. Dissolves organic mud deposits, reduces nutrient reservoir in lake bed deposits, increases dissolved nutrients, for rainfall to dilute out of the lake. This reduces an underlying cause of water quality problems. In combination with SD1, can avoid the need for expensive dredging.
 DuckweedDuckweed Control  

The SD1 and Microchalk products should be considered and used as balancing products for the organic inputs. Once the lake has been brought back into balance, maintenance treatments are done as and when necessary. The lake will then be restored as a beautiful asset, rather than a liability.
Results can be very rapid, and stale fisheries transformed overnight after Microchalk treatment. We have had many reports of angler's catch rates suddenly jumping the day after treatment. Black mud exudes hydrogen sulphide ('bad-egg' gas), which has been proved to inhibit feeding in with fish. If you have black mud (usually 4 or 5cm below the mud surface) you need Microchalk and SD1.

In still waters, problems with algae result from an imbalance in the aquatic ecosystem. Where there are insufficient waterweeds present, algae are the first to 'grab' nutrients when temperature and light increase in the spring. Rapid growth of algae can quickly shade or smother waterweeds, making algae the dominant recyclers of nutrients. If this annual cycle can be broken, waterweeds can re-establish a long-lasting balance.
The use of decomposing barley straw is a scientifically proven technique to control aquatic algae. When breaking down in the presence of sufficient oxygen, barley straw yields by-products that block the growth of green-water, blue-green and filamentous ("blanket weed") algae.

However, this approach has several drawbacks, including:

X Using crude barley straw is inconvenient. It must be handled, put loosely into net bags, made to float (eg with plastic drums) and then distributed around the water to be treated. These nets are unsightly, and prone to snagging by anglers, for example.
X To be effective, the barley straw must break down under the right, oxygen-rich conditions. If these conditions are not present, the barley straw may just add more nutrients to the water, and so feed the algae !
X It usually takes many weeks for decomposition to begin yielding anti-algae compounds.
X The potential capacity for yielding anti-algae compounds can vary greatly between batches of straw.

excalibar is -

- an established, environment-friendly extract of barley straw preparation to fight and control algae*.
- not a herbicide. It comes as an easily-applied solution, and is harmless to fish and other animals.
- produced under carefully controlled conditions, and is batch-tested to MAINTAIN CONSISTENT CONCENTRATIONS OF ANTI-ALGAE COMPOUNDS.
- 100% active from the moment it is poured into the water, and blocks further growth of the algae present*. Because it does not directly kill the algae, excalibar should ideally be used as a preventive tool, and added in the spring, before the algae begin to grow strongly. It can still be used under algal bloom conditions, but may take some weeks to bring the bloom under control, as the algal cells expire. Suspended algae (green and blue-green species) succumb to excalibar more quickly than filamentous types.

* Some species of algae, for example some diatoms (which are brown in colour) are unaffected by compounds from decomposed barley straw. Suspended solids could also reduce the effectiveness of excalibar.
However, our Water Testing Service can resolve any uncertainty about water quality prior to treatment.
We offer a range of tests, from simple identification of species, through to determining an effective dose of excalibar for your water type.
excalibar complements other Pond Healer Remedies and water management products, such as aeration equipment.


Please note that these testimonials were taken from our broad base of satisfied customers after the freak hot weather and drought conditions of 2003. These conditions were ideal for the proliferation of algae.
In untreated still waters, this resulted in blooms of filamentous, blue-green and green water algae. This made the water at least inconvenient and unsightly. They even resulted in the water becoming toxic or deprived of oxygen, thus killing all the fish and other aquatic life.

Thursland Hill Farm - Mrs Bannister. Used 4 years running (2 by the present owner, Mrs Bannister. “excalibar is fantastic, and gives us absolutely superb water quality – gin-clear. The nice thing is that we don’t have to use bales of straw. Other local fishery managers tell us that anglers complain when they catch their hooks in them ! I start treatment before the algae gets going in mid-February, and it only takes me 10 – 15 minutes once a week to treat our two lakes, one of about 1 acre, the other about ? of an acre”
Thanet District Council. A spokesperson: “We have used it very successfully in 3 different town centre water features to control nuisance blanket weed. We will be using it again this year”

Oddfellows Angling Club. One of our first customers, Oddfellows AC will be using excalibar for the fourth year running in 2004. Their fishing lake used to be subject to masses of filamentous algae. Mr Lawson says of excalibar, ”It has been a great success. The lake used to be virtually unfishable when the algae was at a peak until we started using excalibar. Now, there is a patch of 2 or 3 square yards on 7 acres ! Absolutely tremendous! Even last year, with the exceptional weather, it was a complete success”.
Sue Cooke and Associates, garden design and land management. The ornamental pond treated is just under 1 acre. Crude barley straw was tried, but it didn’t work very well. “We have found excalibar extremely helpful, and we are very pleased with it. There is a water garden supplied with water that flows from the lake, and we have found much less algae build up on the waterfalls and water features. We spend much less time scraping algae off, and we have no problems with pumps blocking with algae. Your idea of using a kid’s drencher water pistol to spread it is good fun, too !”

Gilcrux Springs Trout Farm Water flows from the trout farm into a sport trout fishery of approximately 0.7 acres. As a consequence the water is very eutrophic (rich in plant nutrients). Mr Pyke’s verdict: “Excellent ! Before we started to use excalibar, the pond bottom used to lift every April to May (a layer of filamentous algae- blanket weed- would rise to the surface, pulled up by bubbles of oxygen). This has not happened since we have started using it. We are delighted !”

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Nutrients are essential to ‘fuel’ the aquatic ecosystem by supporting phytoplankton which sustain zooplankton, fish and higher animals.    However, when they are present in excess they make water eutrophic, and vulnerable to prolific growth of algae (‘green water’, blue-green and filamentous) and nuisance weeds.
Problem-causing algae in ponds and lakes usually bloom if the ecosystem is not in balance.  The excess nutrients responsible can enter the water from run-off from agricultural land or septic tanks, decomposing plant and animal matter, fish waste, uneaten angler’s baits and droppings from waterfowl. 
swarm is our trade name for a product that has been developed and used over the last 23 years, mostly in the USA.  swarm is a blend of active bacteria that consume nutrients, thus reducing the scope for blooms of algae and weeds.  The key feature of swarm is that the active bacteria are delivered in vast numbers, and alive.  It is therefore applied as a ready-made, dominant life form, thus removing any uncertainty of the growth and establishment of the bacteria if delivered in dormant ’seed’ form. 
Because the swarm bacteria perform the role of nutrient scavengers, they may be thought of as probiotics, keeping the aquatic ecosystem balanced. swarm contains no pathogenic (disease-causing) bacteria, is safe in use, and does no harm to the environment.   Although billions of active bacteria are supplied, they cause no significant turbidity of the water.  The microbes in the formulation are selected in part because of their high specific rates of nitrogen and phosphorus consumption compared with those naturally occurring in the aquatic environment. By comparison with most similar species they have a high activity rate over a broad temperature range, making swarm a good, workable product.  Whilst the microbes compete very effectively for nutrients, they also have another important capability.  Included in the formulation are microbes that decompose organic wastes, such as accumulated sludge.  This can be expected to result in the added benefit of a progressive reduction in organic deposits in the lake.
Treatment can begin once the water temperature has risen to 10°C in the spring, favourable to the proliferation of the bacteria. Ideally, this is timed to pre-empt the growth of algae.  It is applied in 2 or 3 doses during the growing season, according to the pressures of temperature and available sunlight for that year.
Please note that this is not an off-the-shelf product, and is produced to order. It contains no disease-causing bacteria, only aquatic bacteria that take up dissolved nutrients, with added bacteria to breakdown organic matter. 
We can offer an application service by fully-qualified personnel from a boat, should it be required (price on on application).
swarm is complemented by a wide range of other remedies.  Our approach to pond and lake management is to consider and treat the symptoms of the problems.  However, we also like to consider and treat the causes, and aim to create an ecological balance, if possible.

pdf download


is a liquid remedy for murky water made from a plant extract, and has special flocculating properties.
When added to murky water, the tiny electrical charges on the molecules of clearfast (like static electricity) make them stick to microscopic particles such as silt, and ‘green water’ algae. They become attracted to each other, stick together to form larger particles and eventually sink to the bottom. Deprived of light, algae die.

Test kits are available, so you can test a water sample before treating the whole water body.
The following sequence shows a test of a 'green water' sample after treatment with clearfast. The tube on the left of each pair in the photographs had clearfast added. The same number of drops of water was added to the experimental control (right hand tube)

clearfastt0_copy.gif clearfastt1.gif clearfast10.gifclearfastt60.gifclearfastt120.gif
Start, time 0After 1 minute + 10 minutes+ 45 minutes + 2 hours

gives very quick results—ideal when used as part of a longer-term treatment programme
has no direct effect on water chemistry, but simply sticks suspended particles together
aids filtration by concentrating suspended solids into larger particles
can remove sharp particles from suspension which would otherwise damage delicate fish gills
is a refined, natural remedy and is harmless to fish and wildlife
When you need your water clear fast, then you need clearfast

pdf download

SD1 – Sludge Digester

The bed of most lakes and ponds is subject to continuous deposition of organic debris and detritus, such as dead leaves, faecal waste from fish, and uneaten bait from anglers. It is common for this to build up over time due to the decomposition processes not keeping pace with deposition (this is especially true of vegetable material). Thus, these still waters can accumulate ever-deeper mud (with increasing oxygen demand by decomposing organisms) and diminishing water depth. Heavily stocked commercial fisheries, with high levels of introduced bait, are especially vulnerable.
If the excess mud is not reduced, water quality and fish health can be badly affected.
Adverse consequences include:
Year-on-year accumulation of mud, due to insufficient recycling by microbes, resulting in steadily increasing demand for oxygen. Decomposition in the absence of oxygen (evident as black, ’mousse-like’ mud) leads to the production of toxic substances, including hydrogen sulphide. It has been proved in aquaculture that this significantly reduces appetite in fish, and they will go off the feed. This can stress the fish (reducing their resistance to disease), reduce anglers catches, and fishery revenue.
Black, anoxic mud can be a ’time bomb’; in hot weather, the water can ’turn over’, mixing the mud with water and absorbing all of the oxygen. This kills fish and other aquatic animals.
Increasing accumulation of organic matter on the lake bed can kill off the friendly recycling microbes, and poison the area, making it a ‘no-go’ area for fish.
Deep accumulations of mud can reduce the space available for fishing
To assist in the management of fisheries, Spirex Aquatec has commissioned a remedy. The result is the SD1 sludge-digesting product. Based on powerful technology used in industrial applications, SD1 contains selected species of bacteria. These can break down organic matter very rapidly, especially vegetable matter, which normally breaks down very slowly. Assuming that the mud is mostly organic in nature, rapid breakdown can be expected, as much as 80% in 1 year. This avoids the costly and invasive process of dredging.
An additional benefit is that these bacteria need, and ‘grab’, many of the same nutrients that algae need. By depriving the algae of some of their nutrients, they can reduce the extent of algal blooms.
The bacteria are so active in SD1 that it is best applied in the spring or autumn when the water temperature is not too high. Otherwise, deoxygenation might result (oxygen monitoring is advisable - we can give guidance before application). By applying in the spring, the bacteria can help to recycle uneaten angler’s baits and fish wastes through the warmer months.
All of the different species of bacteria selected for SD1 have been isolated from natural sources, and are completely safe for the user.
The performance of SD1 can be improved even further when it is used in conjunction with another Pond Healer Remedy, Microchalk. This calcium carbonate preparation is ground so finely, that the average particle size is 2.8 microns—less than 3 thousandths of 1 mm ! This creates ideal conditions for SD1 bacteria to work to their maximum rate. See separate sheet for details
SD1 complements the wider range of Pond Healer Remedies and water quality management tools from Spirex Aquatec that help to maintain the balance in commercial fisheries, keeping the fish, anglers and Manager happy!

pdf download


In nature, after lakes and ponds are first formed, they follow a process of succession of habitat. Ultimately, the lake becomes filled-in with silt, trees become established and it becomes land .
Thus, in many lakes and fisheries deposition of organic matter in the mud is greater than the pace of decomposition. As a consequence, the mud becomes progressively deeper and the water shallower, allowing marginal plants to ‘walk’ into the lake. This reduces the amenity value of the pool.
Adverse consequences include:
Year-on-year accumulation of mud, due to insufficient recycling by microbes, results in steadily increasing demand for oxygen. Decomposition in the absence of oxygen (evident as black, ’mousse-like’ mud smelling of rotten eggs) leads to the production of toxic substances, including hydrogen sulphide. It has been proved in aquaculture that this significantly reduces appetite in fish, and they will go off the feed. This can stress the fish (reducing their resistance to disease), reduce anglers catches, and fishery revenue.
Black, acid, anoxic mud can be a ’time bomb’; in hot weather, the water can ’turn over’, mixing the mud with water and absorbing all of the oxygen. This can kill all of the fish and other aquatic animals.
Increasing accumulation of organic matter on the lake bed can kill off the friendly recycling microbes, and poison the area, making it a ‘no-go’ area for fish.
Deep accumulations of mud can reduce the space available for fishing
Microchalk is one of the Pond Healer Remedies that can reverse this process. It is a very high quality product, and is virtually pure calcium carbonate ground extremely finely. It is not ordinary ground chalk. The average particle size is 2.8 microns / less than 3 thousandths of 1 mm ! Consequently, it has a vast surface area, allowing it to dissolve more easily, and work more efficiently. Other, inferior products leave lumps and white residues.
Microchalk is alkaline, and works by neutralising the acids in the mud and adding oxygen.  This changes the chemical environment from a reducing- to an oxidising environment.  This becomes favourable to the decomposition of the organic matter by aerobic bacteria.
It is best applied between early winter and spring. It is mixed with the water and spread over the whole lake. We offer an application service, if required.

 25kg paper sack of Microchalk Microchalk is safe to apply (unlike agricultural lime which can burn
those applying it and the fish), and this is most easily done
with a boat with outboard motor

Application of such products can yield spectacular results. For example, organic mud has reduced in depth by 1metre over a 10 year period in one test lake.
Fish and other aquatic animals produce toxic ammonia as a waste product. They depend on this to be recycled through to nitrate (‘nitrification’) for their well being and the balance of the ecosystem. The natural process of the nitrogen recycling by bacteria needs a ready supply of carbonate, and Microchalk provides this in abundance. Where carbonate has been previously exhausted, Microchalk ‘kick-starts’ nitrification back into action.
Microchalk can also improve clarity, by a process of flocculation, where suspended solids clump together and settle out.
* For ‘turbo-charged’ sludge reduction, consider another Pond Healer RemedySludge Digester - please ask for details.
Microchalk complements the wider range of and water quality management tools from Spirex Aquatec that help to maintain the balance in commercial fisheries, keeping the fish, anglers and Manager happy!


Every customer who has used Microchalk has been delighted with the results. Here are a few examples (each one received no payment for their testimonial !) :

Mark Simmons, Heather Fisheries (fish farmer): “We have a pond which had horrible rancid mud in it and was ‘dead’. We applied Microchalk and it made a real difference. We have managed to get weed growing, and had a spawning of tench for the first time in several years. We used to use lime, but the Microchalk is safe to use and has given us better results. We are very pleased, and will be ordering more for next season”.

Murray Marvell, Moorhall and Belhus Angling Club: “In recent years, our lake has suffered from blooms of blue green algae, and we have had areas of deep black mud. The water weeds had died back, we had lost some fish and the water clarity was poor. We dosed the lake with Microchalk in April/May, and within 6 weeks, the water weeds began to grow again. The clarity of the water improved, we didn’t get the blooms of algae that we normally do, and the silt was reduced. Other fishery managers who saw the results couldn’t understand why we didn’t have residues on the lake bottom like they had after using a different product. Even the EA couldn’t believe the improvement in water quality !”

David Midgley, Fishing in France (fish farmer, fishery owner) “Application was extremely easy, and the results have been superb. Before treatment, the lake water quality was dire, with a pH of 5.4 (!), murky and fairly lifeless. After treatment, the pH rose steadily to the mid 7s, and the productivity of plant life (marginal and water weeds) and invertebrate food, like snails, increased. The water is now less murky. Microchalk is an absolutely brilliant product !”

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Duckweed Control

Duckweed is a sign of accelerating stagnation, and indeed will 'kill' a pond if allowed to completely overgrow the surface. This occurs because it 'suffocates' the pond by preventing the exchange with the atmosphere of gases, especially oxygen . Those whose ponds are affected with duckweed realise that regular mechanical removal is extremely time-consuming and hard work ! We can now offer a remedy.
Spirex Aquatec's Duckweed Control controls the growth of duckweed. It contains specialised microbes that consume the vital micronutrients that the most common species of duckweed need to grow. It contains no pathogenic bacteria.It is a liquid formulation, and completely harmless to all fish, amphibians, invertebrate wildlife and other plants in the pond. It is not a herbicide. 
Prior to treatment, as much duckweed should be removed from the pond as possible. Duckweed Control is then applied, weekly. The duckweed that has been removed should be taken away from the water catchment area of the pond, to ensure it does not decompose and re-introduce nutrients to the pond.
Duckweed Control should be used as part of a wider programme, designed to reverse the process of stagnation. Commonly, the bed of affected ponds has excessive deposits of organic mud, which is usually black and stinks. This indicates that there is insufficient oxygen for clean breakdown of the organic material. Spirex Aquatec's Microchalk will dissolve this black mud, so highly-expensive and messy dredging is unnecessary. excalibar will block the growth of algae during the re-establishment of an ecological balance. Please consult us for more details.

Available in containers of 5 litre (treats 10,000 gallons / 45,000 litres) and 25 litres.

Site Visits

Every year we have calls from people who have tried many remedies of other manufacture which have failed to bring the desired results - they have been working on a 'trial-and-error' basis.  This can be very expensive, waste time, and the problems may get worse.  A site visit can be very cost-effective, and get to the essence of the problems very quickly.  See Site Visits for further information, or call us.