UPDATE 2/7/10
Fortunately the filter units could be installed whilst the first fill of the pond commenced. Once again, there are six 4” lines entering from the custom-made special bottom drain and each line enters its own dedicated ‘Eric Four’ filter unit.
It is worth mentioning that the Eric units operate as fully stand-alone filters, NO other items are necessary either before or after these boxes.
The U/V systems and heating systems are supplied their water from pumps powering the surface skimmers on the pond.
When this installation is finally completed and the large courtyard finished it will be easy to walk or drive around the entire pond. Those viewing the pond really only wish to see the pond, the water and the Koi – the very last thing anyone should wish to see are filter boxes; air pumps; water pumps; pipelines; valves; U/V units; electrical power lines; heat exchangers etc. etc.
This is the reason as to why the filter area has been tucked some 25 metres away in the corner shown. Eventually there will be a building around it with access door that matches the adjoining office building in order to disguise it further.
(Admittedly I am greatly ‘miffed’ that my truly magnificent black boxes will be hidden from the view of all who see the pond. I have considered putting a very inconspicuous and tasty neon flashing sign on top of the fountain, you know, around 2m x 2m that revolves endlessly and flashes out ‘Filtered by Eric’ in different colours – but somehow I do not think that this is what the owner has in mind. – pity!)
Because of this distance between pond and filtration area, whilst there are no problems in supplying each unit with water by gravity from the pond drain, it does necessitate using return water pumps that are man enough to get the 1,500 gallons (6,800 litres) per hour of water back through the 2” bore lines to the returns in the pond wall which enter at 70cms below water level and are spaced evenly around the entire pond perimeter.
(In a normal situation where the pond is near to the filter system, 1,500 gallons per hour is, of course, child’s play to achieve. However, in this installation the friction loss produced by the long pipelines, the necessary fittings and the resistance of the pond water pressure at 70cms below the surface requires water pumps that can deliver much more than standard pond pumps.)
‘Techie Stuff’.
I need a total pond turnover (through the filters only) of once in every 2.5 hours in order to give the required dwell time in and through the EricMat blocks and that computes to a little over 1,500 gallons per hour to each river. (23,000 gallons pond divided by 2.5 hours gives 9,200 gallons per hour – divided by 6 for each unit = 1,533 gallons per hour per unit.)
Bearing in mind that each ‘Eric Four’ river holds 114 gallons (510 litres) and water travels through each river as a forward-moving 20” x 20” (50cms x 50cms) ‘Block of Water’, the time taken from start of box to end of box (One ‘PASS’) is 4.6 minutes – or a little over 13 ‘Passes’ per hour and 312 per day at this flow rate.
As each river is 80” (203cms) long, the ‘endless flow’ through each river means the block of water travels a little over 2,000 feet per day through each river giving an annual travel of 143 miles. In this installation there are six rivers so the total travel per year on this system is 863 miles.
Having mentioned on the ‘Flow Patterns’ page that the moving block in Eric units is 85% efficient as to ensuring incoming pond water comes into contact with the biological media before it exits, there will still be an estimated 15% of motionless (useless) water in each unit at all times. In Eric units this is almost irrelevant, as each river (lavatory) will be completely discharged (flushed) to waste every 24 hours. This means 680 gallons per day on 23,000 gallons in warm water, high stocking and heavy feeding times or maximum demand on the system. In lower demand situations – cooler water/low stocking/moderate feeding etc. then each river can be discharged every two days which means that 340 gallons per day will be discharged to waste.
If we take maximum demand periods as an example, 680 gallons each day is only 3% of the total pond volume. The circular pond depth is 80” (2.05m) deep and 680 gallons represents a 2.4” drop in water level after a total discharge of all six units (0.4” per unit). Even with a total discharge of all six units the water pumps are still in full prime and ready to be switched on again without any time wasted waiting for ‘topping up’!
It is vital for the efficiency of the backwash to the brush boxes that the 4” bore drain outlet is kept to that bore. Assuming this to be the case (as it is in this installation) then the total time taken to empty and re-fill each unit from pump stop to pump start is a fraction over one minute. In this example of six rivers facing maximum demand situations it takes 6.5 minutes per day in order to maintain all rivers as becoming ‘brand new’ on a daily basis.
Do consider once more that there are 312 ‘PASSES’ through one river in any day and each ‘PASS’ takes 4.6 minutes. The one-minute discharge time only represents 25% of one pass and that will ensure total cleanliness of the part of the system where wastewater should be removed from, namely ‘the lavatory’. Incidentally, these units cannot block or overflow even if left unattended for some months, however this is not recommended at all. Just consider a lavatory in use every day without being flushed!
Replacement mains water is trickled in constantly to bring the system back to just over final level with some tiny excess to pass to waste via the overflow. In this installation the trickle will be set to 700 gallons per day at maximum demand times which is 0.5 gallons per minute. Mains water purification units are not necessary on Eric systems.
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Incidentally, I am well aware of what is required to install such a system and also painfully aware that there are few around with the ‘nouse’ of young Matt Cameron who is the guy responsible for this work of art – which it is. Some weeks back I re-named him ‘Filter Matt’ – the highest accolade I could come up with!
Filter Matt was on duty on my stand at the National Show recently and I overheard him mention to someone that he knew far more about Eric than I did!
(The Fool – he needs bringing down a peg or three!)
Of course, I could have done all this in half the time had I not been extremely busy with my latest venture as authorised area distributor for Surecut Spades!
