Pumps

Coltiva can control up to eight pumps. The seven outlets numbered 1-7 are for pumps that run on request, from the app or by automation. These can be used to, for example:

• Refill the reservoir with
  • nutrients
  • pure water
  • pH adjustment
  • other additives
• Empty the reservoir

Additionally, there's one outlet labelled "circ pump", which is intended for a centrifugal pump used for circulating the nutrient solution (for small reservoirs). The circulation pump runs all the time, except for when:

• Another pump is running
• The sensors are being read, about 30 seconds every 4 minutes

Dosing pumps (peristaltic)

Peristaltic pumps are intended for precise dosing of concentrated nutrients. The minimum recommended dosing volume, to achieve good accuracy, is 5 ml. It is possible to pump down to 1 ml nominally.

Volume pumps (centrifugal)

Centrifugal pumps move water in volume: circulating, refilling or draining the reservoir. They have a minimum dosage volume of 0.5 L. If 0.5 L is more than you want to add (e.g. for pH adjustment liquids and concentrated nutrients), dilute your solution so that 0.5 L of the diluted solution corresponds to the minimum amount you want to be able to pump.

Avoiding siphoning

It is very important to not mount the end of a refill or drain pump's hose lower than the water level of the tank that it is pumping from. This causes the refill liquid to continue flowing into the reservoir, even after the pump has been shut off.

Instead, place the refill tanks so that the end of the refill hose is higher than the liquid level in the refill tank.

Alternatively, if it is not possible to have the refill tank's liquid level lower than the hose end, you can prevent siphoning by allowing for pressure equalization. Install a T-connector at the highest point of the hose, and attach a piece of hose with the other end open. Attach the open hose end at least 1 m above the T-connector.

It is equally important to not let the end of the refill hose be submerged in the reservoir solution. This can lead to backwards siphoning, meaning that the reservoir liquid flows backwards into the refill tank.

Mounting

The pumps may be mounted with magnets (easier to attach/detach and usually more reliable) or suction cups.

Mounting with magnets

To mount using magnets, your pump platform must be equipped with magnets.

1. Position the magnets

   Attach the magnets that you're going to mount to the pump platform magnets. The magnetic force will hold them firmly in place, and make sure that the magnets that you're mounting are mounted with the correct layout.

2. Prepare the surface

   The surface to which you're attaching the magnets must be prepared for maximum adhesion. Please see Preparing surfaces for gluing or taping.

Calibrating a pump

The device doses by running a pump for a calculated time, so it must know how much each pump moves. Calibrate every pump before you use it, and again if you change its tubing. A pump that is not calibrated cannot dose, neither by hand nor by automation.

1. In the app, open your grow system, tap Pumps and pick the pump.
2. Tap Calibrate and choose the pump type. A peristaltic pump dispenses about 75 ml, so catch it in a 100 ml measuring cylinder. A centrifugal pump dispenses about 1 litre, so use a container with volume markings that holds at least 1.5 litres.
3. Choose Calibrate by measuring. The pump runs for a fixed time.
4. Measure the dispensed volume, enter it and tap Submit measurement.

tip

If the tubing is empty, the first run mostly fills the hose and your measurement will be too low. Choose Use factory default first, run the pump by hand until liquid comes out at the far end, then tap Recalibrate and measure.

Running a pump by hand

Open your grow system, tap Pumps and pick the pump. Enter an amount, choose ml or L, and keep Hold to Run pressed for a second or so. The pump runs until it has moved that amount. View pump run history in the pump list shows the runs of the last 7 days.