I will teach you my method of watering plants automatically.
Here's what you will need
Trash can reservoir
Submersible pump
1/2-5/8 in flexible hose. The hard plastic stuff will work but this flexible rubber hose is better imo. The smaller pump with the line attached to it in the pic is a smaller version for clones and seeds. I use the larger pump for up to 25 plants. It could easily do more but that's about the most I've tested it on.
1/4 inch hose
1/4 in T or Straight spikes for the hose to plant out of the 1/2-5/8 inch hose.
Air check valve. This is used to break the syphon. You can find it at a pet store in the fish tank supply department or at An auto parts store. They are 1/4 in.
Plug for the end of the 1/2-5/8 in tubing with metal tube clamp
Tall boy filter made by hydrologic.
Timers seconds timer( online) or minutes timer.
Hose bib timer
Small hose from filter to can and another hose from hose bib timer to filter.
How you set it up.
Reservoir can gets set up first in location where ever you want it.
Next set up tall boy filter
Attach 1/2-5/8 in hose on to submersible pump and Put submersible pump into the reservoir
Attach air check valve out of the reservoir at its peak height.
Run 1/2 to 5/8 in hose around plants.
Spike in 1/4 in T or straight spike into 1/2-5/8 hose at location of each plant or couple of plants.
Put stopper with clamp on the end.
Set hose bib timer
And timer on pump
Time how long it takes to fill the reservoir.
Keep note on how long it takes for it to empty. Coordinate with how long it takes to empty to keep it full. If you need to add a minute or take a minute to make adjustments.
Seconds timers work well on the smaller kits. For the larger kits it's ok to use a minute timer as long as you have larger pots and when you transplant that are teen sized plants and can handle the amount of water. I've found it's tough to overwater the soil in 20 gal pots if you run on one minute or less in increments throughout the day on a large pump. To limit water for plants that may not be as thirsty you
can put a screw in one end, or you can buy plugs that will go into the 1/4.
This is from last seasons grow in my new greenhouse!
I started my plants as seeds inside in June and then put them outside in July and harvested in October. This unit hasn't changed for a long time besides switching to rubber hose.