EFM Scientific Data

Ebb And Flow Mat Vs. Traditional Capillary Mat (sand bed)

Bottom Up Irrigation Systems Explained

System	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. This mat may be placed on any level or moderately sloping surface of reasonably even grade, indoors or outdoors.
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.
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/siphoning effect when irrigation ceases. This drainage method brings pots to a favorable level of air filled porosity.
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 drains 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. It can be placed outside on ground, benches or indoor in any number of configurations.

How KISSS Ebb and Flow MAT is outperforms other capillary systems.

	Traditional Capillary Mat (sand Bed)	KISSS Ebb and Flow MAT™
Suitable for:	Greenhouses, with limited outdoor application	Greenhouses, Outdoor Nurseries, Retail Nursery's, and Home Owners
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, run-off is minimal and controlled.
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, hardens 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.
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.