I predict you will get seriously tired of managing 8 individual buckets, both nutrient levels, and pH. And here's the thing, small amounts of water swing a lot! Meaning that pH and PPMs have the potential to go up and down multiple times a day, and when you add small amounts of nutrients. You'll also have to keep each one filled, and during flower, they can go through gallons. One more thing, heat. You need to keep the water around 69 degrees, otherwise you get all sorts of problems with the roots, that have drastic effects on the plants. I keep thinking of points LoL! Something else you'll have to deal with is lifting the lid on each one, each day. When the plants get big, with heavy colas, it's no bueno to be shifting them around. And another thing, you're going to be squating on your knees, for extended times, managing each individual bucket. It's going to take you so much more time to manage. It's especially hard to manage buckets in the back.
I point all these things out, because I want you to start off on the right foot. You don't want to be spending all your time managing your buckets, leaving lots less time to learn how to grow these plants, which takes lots of practice.
There is no need to manage nutrient levels individually. Start your plants at the same time, and use similar strains, so you don't have any outgrowing the others. Their nutrient needs will be the same for all of the plants.
With that, you should seriously consider going RDWC, where everything is connected, and you manage the levels of the whole system, in a single "controller" bucket or tote, making it much easier to check levels. You only need to fill the whole system from one point, and it's much easier to manage water temps, with large volumes of water.
Finally, you might want to rethink using buckets, and use HDX 27-gallon totes instead. You can hold much more water in the same space two buckets occupy.
You can still have individual air pumps. Many people do that. But you'll need a small water pump to circulate the water through all the connected containers. Nothing big, because big pumps create heat that you have to fight.
Check out my thread. It has a ton of information and pictures. I explain things in great detail, and have a lot of input and feedback from experienced growers. My original design used buckets, but I switch to the totes around page 10.
It's really important you think about this now, because once you're in the middle of a grow, it gets much tougher to work on things. Good luck.
I've got an Active Aqua 60W, 70 L/min pump coming for my 4x5 gallon bucket UnderCurrent build. An 8 output manifold comes with it. What I'm wondering is, would 2 air stones per bucket produce more dissolved oxygen than 1 air stone per bucket at twice the pressure (because 4 of the outputs...
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