There are two basic types of hydroponic drip systems, Non-recirculating and recirculating [recovery drip systems]. Of course there are many variations of each type but theses are the 2 basic ones.
The recirculating drip system reuses the nutrient solution. It is collected in a small reservoir and recirculated back over the media. Recirculating systems are considered to be more efficient by some in that it does not waste solution, but it has multiple drawbacks in comparison to simple drip systems.
There are two basic types of hydroponic
Comparison Hydroponic Recirculating and Non Recirculating Systems
The pH and nutrient strengths fluctuate so need to be constantly monitored and frequently adjusted. Additional labor is required in maintaining the solution, be it adjusting pH and nutrient levels / strengths or periodic flushing to avoid mineral buildups and replenish nutrients.
Non-recirculating drip systems are more common, and in my opinion the best way to go if you choose to use drip. Although water and solution is not reused in non recovery / non recirculating systems there is actually very little waste
Precise timing of water cycles coupled with the correct medium assures that very little solution goes to waste. Allowing for a drip flow that wets the media without allowing for very much run off is the key. Once you get your system set up you’ll have to tweak it a tad to get the time / water / nutrient ratios adjusted to your particular circumstances.
Smaller, multiple applications have proven to increase yield in most crops. Tomatoes for instance have increased yields of 8% to 12%.
A Japanese study ‘Influence of single and multiple water application timings on yield and water use efficiency in tomato’ [See: Agricultural Water Management] demonstrated the effects multiple water applications ‘the DT was the best irrigation timing because it increases the tomato yield by 8% and 12%’.
Cycle timers are not all that expensive and are used to precisely adjust the drip flow. Flushing the solution and growing media is still required periodically to avoid nutrient build up over time. [See: Water Timers ]
The water in the reservoir also needs to agitated and moving to prevent heavier and lighter minerals from separating in which case the heavier ones will fall to the bottom and not be present in the drip delivery.
A slow draining medium is needed, Perlite/vermiculite or Rockwool works well, Organic media such as peat or coconut coir also work but sometimes add to the issue of clogged drippers.
Drip systems become clogged due to particles from nutrients and organic matter that build up in the emitters. Systems that use organic nutrients and media are more prone to clogging.
A blend of Perlite and vermiculite works very well, some growers also blend it with coconut fiber [coco coir] or peat moss. Perlite is fairly inexpensive but doesn’t retain water that well.
Vermiculite retains water so when blended with perlite the two complement one another and make good hydroponic media for drip systems.
A drawback to perlite is that emits an unhealthy dust [to humans] that also contributes to drip clogging, some growers add additional filtering for this reason. Screening, mesh, durable porous geotextile fabric /cloth, that will allow for the flow of water and trap unwanted particles.