Sounds good. Yes, I wouldn’t want to use toilet water, but bath and shower water would be ok. Just remember when you’re cleaning the bath with bleach or similar, send that water back to the normal drain!

Kitchen water from washing up should be fine, just watch that you don’t put too many fats down the drain, as it could smell and attract rats etc, possibly (just guessing, but I would think it would be a bad idea).

Also, i guess you need to think about the temperature - you don’t want hot water near your plants!

Next year I should think about doing the same thing with shower/bath water at least, that is probably the cleanest waste water.

If you just want to use an earth channel or similar, maybe have a look at “Field Drains”, eg: https://store.jdpipes.co.uk/land-drainage/ ? although you might have to get access to them now and again to clear the holes.

Fair enough, and with underground tanks you need a way of getting the water out again, which usually means pumps, which adds expense and maintenance, and you have to make sure the water is really clean.

Using greywater is sensible. Switch your soaps to nature-safe ones to help - https://www.faithinnature.co.uk/ make some good hand, shampoo and dish-washing soaps. I really like the solid shampoo bars from here: https://www.soapnuts.co.uk/products/bulk-mixed-shampoo-selection too.

You can also get filters to help get rid of the impurities. One system is using a reed bed if you have space: https://www.reedbeds.co.uk/

https://www.hockertonhousingproject.org.uk/ has such a system as part of their pond system. We went on one of their open days a few years ago, which was really interesting.

Our UK garden is about 75x75m, which is a decent size, but not massive. About half to 3/4 of it is grass, which I hardly ever water, and haven’t this year even though we had a drought.

We have 5 IBCs, and several other randomly-sized water butts (~7000l total (1500gal UK, 1850gal US)), to keep our veggies and fruit bushes watered. We ran out this summer, and had to use about 500l of tap water until it rained again :(

Dry periods are likely to get worse in future, so I need to get more water storage. I also want to start using rain water to wash clothes (or at least fabrics we use for our pet rabbit houses), but I need a good filtering system first.

We have 2 IBCs stacked, and I was trying to use the top one to gravity-feed our downstairs toilet cistern for flushing and worked well, although it took 7 minutes for the cistern to fill, which isn’t great if you have to accommodate a lot of people. It is good enough for us though.

I could add a pump to speed up the process, but I’m trying not to add more cost and complications to the system unnecessarily.

I can fit 1 more IBC in somewhere - they don’t look pretty, but they are very practical. I normally transport them home on the top of my car on a roof-rack… and drive slowly! :)

It would be good to know which wifi controller and “alternative controller” you are planning to use. I’m after one, but so far, most of them I have seen need crappy apps. I want mine to use an open API etc.

You can also buy IBCs with galvanised sides, which is pretty cool. They can be £10-20 more expensive, but makes the whole thing more robust, in my opinion.

Eg: https://smithsofthedean.co.uk/product/ibc-tank-1000-litre-galvanized/

Ours have little holes drilled in the front side every 100l to expose the plastic tank underneath, so you can see the liquid level.

I would recommend this type so you don’t need a separate cover, which could get ripped etc.