Attribute |
Traditional capillary mat (sand bed) |
KISSS EBB and Flow MAT® |
Appearance |
A level surface with side walls is prepared so that it is impervious to water (e.g. fiberglass) or covered with an impervious plastic layer. |
The Ebb and Flow MAT irrigation system is delivered cut to size and ready to connect to external water. It comprises a three-layered mat and a regulated water supply built into the edges and in some cases in the center of the mat. This mat may be placed on any level or moderately sloping surface of reasonably even grade, indoors or outdoors. It can, if desired, be placed on top of existing greenhouse benches or external ground cover. |
Water Introduction |
A sponge-like 'capillary' mat made of natural or synthetic fibers and 3 to 6 mm thick is placed on this surface. Water is added to thoroughly wet this mat, a process that can take a relatively long period. |
When connected to external water, the central layer of the mat distributes the water evenly throughout the system. A lower layer of impervious plastic prevents the water from escaping, and the top layer, made of ground cover, sits above the water providing a barrier against evaporation. |
Water Delivery |
Pots with bottom drainage holes and containing pot mix and plants are then placed on the mat. Water emanating from the capillary mat is brought into contact with the pot mix, and moves by capillary action throughout the pot, in doing so providing water to the plant's root zone. |
When pots are placed on the Ebb and Flow MAT, the top layer is brought into contact with the capillary layer, and water is forced up directly under the pot and around the rim of the pot. Water passes through the bottom and/or side drainage holes of the pot into the potting mix and up to the root zone of the plants. |
Drainage cycle |
In some cases, a black perforated plastic sheet is placed on the capillary mat before pots are added. This sheet is to minimize evaporation and algal growth without preventing water flowing through perforations and making contact with pot mix. |
The mat is tailed off at one end or side to produce a drainage or siphoning effect when irrigation ceases. |
Irrigation period |
Water is added continuously to prevent breaks in capillary flow from the mat to the plants. |
Irrigation periods are shorter than with overhead or capillary irrigation. When irrigation ceases, the mat and then the pots drain gently, leaving pot mix with a good air filled porosity. |
Placement |
Capillary mat irrigation is normally used in greenhouses. However, capillary irrigation of a similar form may also occur outdoors, using sand beds to act as reservoir, with a black perforated mat placed between the capillary mat and the pots. |
KISSS Ebb and Flow MAT can be placed on any surface that is even and provides reasonable support. can be placed outside on ground, benches or indoor in any number of configurations. |
Suitable for: |
Greenhouses, with limited outdoor application |
Greenhouses and Outdoor Nurseries |
Surface: |
Level surface required |
Works on level and sloping surfaces |
Closed or Open system: |
Growing area is enclosed on all sides to contain water |
Growing area can be open on one or more sides, but run-off is minimal. |
Investment required: |
Large relative to overhead irrigation. |
Low relative to overhead, capillary and ebb and flow systems. |
Wetting period: |
Continuous. System should never dry out. |
Short periods of wetting followed by slow drainage. |
Pots/containers used: |
Requires special capillary pots. |
Any pots with bottom and/or side drainage holes. Successfully used with plug trays to 2-gallon containers and above. |
Surface care: |
Surface of mat should not dry out as this will disrupt capillary connections. Needs attention and should be kept free of debris. Algae need regular removal. |
Tolerant of debris and careless housekeeping practices. Surface of weed mat is allowed to dry to save water, harden plants and discourage algal growth. |
Saturation: |
Mat is always saturated. Pot mix normally contains 30% moisture in bottom half, 25% in top half. |
Saturated zone is very small ( 2mm), and occurs only during the short period of irrigation. Water is taken up by pot media at its natural capillary rate. Flooding does not occur so air filled porosity is high. |
Plant stress: |
Minimal moisture stress (soft plants). A perched water table is maintained, with potting mix never draining completely. Excessive succulent growth experienced with some plants |
Regular, periodic moisture stress allows plants to be hardened slowly over full growing cycle. Water availability can be managed, as required. |
Root growth: |
Restricted by large saturated area. |
Volume available for root growth is relatively very large due to lack of large saturated portion. |
Salts build-up: |
As water direction is the reverse of that under overhead irrigation, salts may build up in pots. Pots should be flushed periodically. |
With small periods of gentle irrigation and longer drainage periods (as against constant capillary activity or flooding), salt build-up is minimal. |
Water available to side drainage holes of pots: |
No obvious free water that can reach side drainage holes. Water take-up from saturated mat is through bottom drainage holes only. |
Free water is visible in a ring around the pot base during irrigation, facilitating capillary action through side drainage holes. Water may also be taken up through bottom holes. |
Drainage: |
No drainage. This can cause problems in heavy rain, as water cannot escape. |
Drainage of mat and pots takes place for most of the irrigation cycle (when Irrigation is turned off). In addition, drainage from the mat is constant whenever excess water exists. Waste water may drain from any point along the fringe of the mat, but the system allows for control and easy capture of waste water. |
Disease exposure: |
Single 'well' of water shared by all plants can increase potential to transmit disease. Constant wetting of pot mix may create anaerobic conditions and encourage bacterial growth etc. Disease may also attack and grow on organic matter trapped within the capillary mat. |
Minimal drainage losses from pots because less of the medium is wet beyond its natural holding capacity. Water is continuously moving and, together with the lack of organic matter in the capillary mat, this reduces the likelihood of zoospores germinating in the system. A relatively small volume of water is retained in the mat when drained. Much of this water is flushed from the mat in the first part of the next irrigation, eliminating potential contamination. |
KISSS Ebb and Flow Mat VS. Ebb and Flow Flood System
Attribute |
Ebb and flow system |
KISSS EBB and Flow MAT® |
Appearance |
A 'tray', with floor and sides impervious to water and a drainage point at the lowest point of the tray, is placed on a level surface. |
The Ebb and Flow MAT irrigation system is delivered cut to size and ready to connect to external water. It comprises a three-layered mat and a regulated water supply built into the edges and in some cases in the center of the mat. This mat may be placed on any level or moderately sloping surface of reasonably even grade, indoors or outdoors. It can, if desired, be placed on top of existing greenhouse benches or external ground cover. |
Water Introduction |
Water is introduced into the tray, rising to a pre-determined level 2- 3 cm. above the level of drainage. |
When connected to external water, the central layer of the mat distributes the water evenly throughout the system. A lower layer of impervious plastic prevents the water from escaping, and the top layer, made of ground cover, sits above the water providing a barrier against evaporation. |
Water Delivery |
Pots are placed on the bed, water rising to cover the side drainage holes, flooding and saturating the bottom of the pot mix. Capillary flow raises water to wet the rest of the pot mix and the root zone. |
When pots are placed on the Ebb and Flow MAT, the top layer is brought into contact with the capillary layer, and water is forced up directly under the pot and around the rim of the pot. Water passes through the bottom and/or side drainage holes of the pot into the potting mix and up to the root zone of the plants. |
Drainage cycle |
After a period of irrigation, the drainage plug is manually removed and the tray drained. |
The mat is tailed off at one end or side to produce a drainageor siphoning effect when irrigation ceases. |
Irrigation period |
Water drained may be recycled and used in other trays in sequence or disposed of. |
Irrigation periods are shorter than with overhead or capillary irrigation. When irrigation ceases, the mat and then the pots drain gently, leaving pot mix with a good air filled porosity. |
Placement |
Ebb and flow systems may be built from a flat fiberglass bench or a flat bench covered with polyethylene, in each case with sides. |
KISSS Ebb and Flow MAT can be placed on any surface that is even and provides reasonable support. can be placed outside on ground, benches or indoor in any number of configurations. |
Suitable for: |
Greenhouses |
Greenhouses and Outdoor Nurseries |
Surface: |
Level surface required |
Works on level and sloping surfaces |
Closed or Open system: |
Growing area is enclosed on all sides to contain water |
Growing area can be open on one or more sides, but run-off is minimal. |
Investment required: |
Large relative to overhead irrigation. |
Low relative to overhead, capillary and ebb and flow systems. |
Wetting period: |
Extended periods of wetting followed by rapid drainage. |
Short periods of wetting followed by slow drainage. |
Pots/containers used: |
May need special pots and media in some situations, but can be flexible. |
Any pots with bottom and/or side drainage holes. Successfully used with plug trays to 2-gallon containers and above. |
Surface care: |
Water and sand needs to be kept clean and free of debris. |
Tolerant of debris and careless housekeeping practices. Surface of weed mat is allowed to dry to save water, harden plants and discourage algal growth. |
Saturation: |
Potting mix is submerged (above drainage holes) during irrigation. Pots wet up rapidly, with pot media flooded past its water holding capacity. |
Saturated zone is very small ( 2mm), and occurs only during the short period of irrigation. Water is taken up by pot media at its natural capillary rate. Flooding does not occur so air filled porosity is high. |
Plant stress: |
Hardening of plants possible through management of irrigation/drainage cycle. Excessive succulent growth experienced with some plants |
Regular, periodic moisture stress allows plants to be hardened slowly over full growing cycle. Water availability can be managed, as required. |
Root growth: |
Restricted by large saturated area. |
Volume available for root growth is relatively very large due to lack of large saturated portion. |
Salts build-up: |
Some build up of salts is possible and periodic flushing is recommended. |
With small periods of gentle irrigation and longer drainage periods (as against constant capillary activity or flooding), salt build-up is minimal. |
Water available to side drainage holes of pots: |
Pots are standing in 3 - 6 mm of water, and bottom part of pot mix is flooded. Water take-up is from both side and bottom holes. |
Free water is visible in a ring around the pot base during irrigation, facilitating capillary action through side drainage holes. Water may also be taken up through bottom holes. |
Drainage: |
Waste water drains from outlet at lowest point. Intermittent drainage (when plug is manually removed). This can cause problems in heavy rain as water cannot escape. Pots with light mix can float and/or tip over. |
Drainage of mat and pots takes place for most of the irrigation cycle (when Irrigation is turned off). In addition, drainage from the mat is constant whenever excess water exists. Waste water may drain from any point along the fringe of the mat, but the system allows for control and easy capture of waste water. |
Disease exposure: |
Single 'well' of water shared by all plants can increase potential to transmit disease. Extended saturation of bottom 2+ cm of pot mix may encourage bacterial growth etc. Recycling of water through other trays provides increased opportunity for disease transmission between pots. |
Minimal drainage losses from pots because less of the medium is wet beyond its natural holding capacity. Water is continuously moving and, together with the lack of organic matter in the capillary mat, this reduces the likelihood of zoospores germinating in the system. A relatively small volume of water is retained in the mat when drained. Much of this water is flushed from the mat in the first part of the next irrigation, eliminating potential contamination. |
