Roof Hydro

• Cheap
• Modular - easy way to pull out and replace rows for cleaning/maitenance, disabling parts of the system.
• Flexible - support different types of plants for experimentation
• Extensible - should be able to build a simple cheap system for a start and add modules as we go

Rooftop is really nice for NFT since it’s already slanted, providing us with a natural waterflow direction for water return. We’d pump nutrients into the system with a simple pump, and return them back into the tank with gravity

NFT is a common cheap industrial and hobbyist hydro setup with lots of resources online, https://duckduckgo.com/?t=ffab&q=Nutrient+Film+Technique&iax=images&ia=images

Here are some samples of how others do this:

Return pipe needs to be at the bottom of the gutter, the gutter also needs to be slightly slanted towards the return end to make sure we don’t have nutrients staying in the gutter

These are born to be made on a cnc since we need many, and they are all the same. I’d suggest something like 8-10mm plywood to start, maybe something recycled and waterproof later, easy to experiment on this.

Medium within the gutters is used only to support the plants, Water retention capcity of medium will dictate the liters per minute we expect the pump to push through.. For example if using expanded clay, we need to have a constant flow of water since it doesn’t retain anything, random sand of different sizes, coco whool, etc will need less throughput.

With valves built into ingress points for gutters it’s possible to control water flow and experiment with different mediums.

With some sort of cover this can also be used for starting plants. part of gutter can be covered, even with simple transparent kitchen plastic.

I’m not sure what sort of filter to use for dirty water coming back and if gravity would be enough to push the water through fast enough.. this depends also on the general speed of water through the system.

We are interested in removing random particles and also to prevent biological contamination and weird stuff growing in the nutrient tank.,

I’d start with just standard kitchen particle filter, something like this https://www.aliexpress.com/item/32721928288.html Using some fine metal mesh cartrige. this would just remove the dirt. We also might want to run a UV light within a tank to avoid biological contamination.

Good thing is that filter is not neccessary and this can be done later, for a start we can just use an unfiltered tank and occasionally change the water. This is what most people do.

There are many pumps to choose from, I’d start with some mega cheap/simple (20 eurish) immersible pump people use for aquariums and later use some stronger pump (50-100 eur) for boats or camper vans. keep in mind that pumps won’t like big particles, some pumps come with embedded small mesh filters.

Having valves to control the amount of flow of nutrients into each gutter individually will allow us to compensate for different heights of gutters

Start small, expand when needed, long term I’d make a hole through the wall or window and keep it within a building for easy maitenance and monitoring.. make sure you have a way of emptying the tank for maitenance

I’d suggest using some sort of quick connects and valves on each gutter element, so that individual element can be turned off and removed

./plans.FCStd