As a city dweller who has grown a lot of plants on balconies and in apartments I have also been down that road but I found a much easier solution to the watering. Autopots[1].
With those you can have 6 plants on a single 47l tank and only re-fill it every month. (depends on how thirsty they are)
It's a gods send when I want to go away for a few weeks vacation.
For other house plants that are not connected to a huge water tank I tend to just turn over a 2l plastic bottle into the soil after thoroughly saturating it first with water.
So with this the only real requirement I had for my grow op was monitoring. Because I have hard wood floors and I don't want them to swell up due to a leaking tank.
For those who don't want to / can't pay for it (eg the developing world), burying unglazed pots will also work. It's probably the most water-efficient method in arid land. The technique is at least 4000 years old.
With those you can have 6 plants on a single 47l tank and only re-fill it every month. (depends on how thirsty they are)
It's a gods send when I want to go away for a few weeks vacation.
For other house plants that are not connected to a huge water tank I tend to just turn over a 2l plastic bottle into the soil after thoroughly saturating it first with water.
So with this the only real requirement I had for my grow op was monitoring. Because I have hard wood floors and I don't want them to swell up due to a leaking tank.
1. https://autopot.co.uk/products/