Filter Selection
To choose the ideal filter for any pond you must first know the correct environmental flow to maintain ideal water quality for your pond. (Please remember that the pond size alone does not determine the filter or pump size without first taking into account the many environmental and physical factors).
3 ways to get help to establish flow
- Fill in one of our e-mail help forms and let us do all the calculations for you
- Give us a call 1800 607 388 for our advice
- Do it yourself and use our quick reference flow calculator for rough estimate.
Step One: Establish the required flow through the filter keeping in mind waterfall** height if any, or long hose**
Step Two: Choose a filter from the chart below (Example if your pond requires a flow through the filter of 3,400 litres per hour, the Pressure Flo 10000 would give the best result)
Step Three: Choose a pump, they are listed below in order of quality and suitability
Suitable Pumps
|
3000 |
6000 |
10000 |
14000 |
Most suitable pumps
Assuming a waterfall is not over 500mm high or the correct size hose is not longer than 3m |
Laguna Maxflo 2200## Oase Aquamax Eco 2500
|
Laguna Maxflo 4000
Oase Aquamax Eco 2500
|
Laguna Maxflo 4000
Oase Aquamax Eco 3500
|
Laguna Maxflo 5000
Oase Aquamax Eco 5500
|
What makes a pump that is specifically designed for sending water to a filter (such as the pumps above) superior to a multi purpose pump such as Pondmate
1) The cage design is turtle shell shaped to attract solids from 360 degrees
2) These pumps are designed to run 24/7 year after year
3) They have a vortex impeller capable of handling solids without blocking
|
Other workable pumps |
|
Laguna Maxflo 5000## |
Laguna Maxflo 5000## |
Laguna Maxflo 7500## |
**Special note, if using a waterfall or a long hose between pump and filter the pump will need to be larger to allow for the reduced flow caused by the head (pumping height, and/or hose length) If in doubt Fill in one of our e-mail help forms and let us do all the calculations for you.
# A little under size for some pond sizes, but would work if the pond were smaller than the filters maximum volume rating.
##This pump is a little too strong, unless a waterfall over 1m is in place. However, you can never have too much pond flow, so, by releasing water back into the pond through a "Tee" and flow valve added circulation is provided for the pond.
|
Recommended Flow Rates
|
3000 |
6000 |
10000 |
14000 |
Minimum Flow |
625 |
1,250 |
2,000 |
3,000 |
Ideal Flow - See hint 4 below |
1,100 |
2,150 |
3,400 |
5,100 |
Maximum Flow - See hint 4 |
1,250 |
2,500 |
4,000 |
6,000 |
Aussie's additional tips
Tip 1: When calculating flow, always allow about a 15% flow loss when a pressure filter is used.
Tip 2: Place the pump at the opposite end of the pond to the water return, and in the deepest part of the pond.
Tip 3: Blagdon Interpet offer a powder to prime filter systems, a great way to hasten biological activity. Tornado Biostim Liquid.
Tip 4: Within reason the slower the water passes over the UV lamp and through the filter the better the result. However, you can never have too much pond flow, so, by having a slightly oversize pump and releasing water directly back into the pond or on to a feature or waterfall through a "Tee" with a valve (tap), added circulation is provided for the pond.
Tip 5: Pump - maximum pumping head. The pump supplying the filter must not have a pumping head exceeding 4m (0.4 bar) Head over 4m could damage the filter and could even burst the container. On the other hand a pump with inadequate head may not provide enough flow through the filter
In a nut shell ....The height difference between the filter lid and a pressure free outlet must not exceed 4metres (0.4 bar). So if the filter was mounted 1m above the pond surface, the pump must not have a maximum pumping height in excess of 5m. Or if mounted 2m above the surface of the pond, the pump must not have a maximum pumping height in excess of 6m.
There is however another factor in head calculations if long hose lengths are used, see "Friction loss in hose" under How to calculate your friction loss if your hose will be more than 3m.
Filter Pond Size Chart
Pond size selection
|
3000
|
6000
|
10000
|
14000 |
No fish* Pond size - litres |
3,000 |
6,000 |
10,000 |
14,000 |
Some fish** Pond size - litres |
1,600
|
3,000 |
5,000
|
7,300 |
Medium fish*** Pond size - litres |
1,000
|
2,000 |
3,500 |
5,000 |
Lots fish **** Pond size - litres |
700 |
1,250 |
2,000 |
3,000 |
Koi/Turtles***** Pond size - litres |
500 |
1,000 |
1,600 |
2,400 |
*No fish - Near natural garden ponds in shade, at least 70cm deep with plant zones, without fish.
**Some fish - Near natural garden pond with plants and fish stock of 40cm per 1,000 litres
***Medium fish - Near natural garden pond with plants and fish stock of up to 60cm per 1,000 litres
****Lots fish - Near natural garden pond with plants and fish stock of up to 80cm per 1,000 litres
***** Koi and Turtles - Pressure filters are not ideal for Koi or turtles due to the extreme amount of waste they create and have trouble processing the waste due to their design , therefore, gravity filters are better suited.
However, due to their size and fact that gravity filters must be mounted at the top of a waterfall or above pond level, there may be no other choice. In this case use a pressure filter but we suggest that the pump and filter be a little oversize maintain water quality.
For Australian conditions... The above figures have been adjusted by us for Australian conditions, please do not be confused by anyone else's calculations that may be for the European market as they are different because of our climate