hiya GB, I fertigated (mix nutes into rez water) my indoor/outdoor weed/veggie SIPs for a couple/few seasons now and the only times I've been able to use liquid organic nutes is if I have a bubbler or pump in the reservoir to keep the aerobic bacteria in the ascendancy and the material itself from layering/becoming sediment. Synthetic nutes work just great on their own without the machinery and some synthetics with organic add-ins like m3gacr0p (the all-in-one line and their two-part, both) work fine too. I don't know which FF ferts you're referring to so I'm giving you the full run-down on fertigation here. Some of my DIY SIP designs have 9 gallons of fertilizers in the onboard rez, so I'm pretty much torture-testing my fertigation - often going 2-4 weeks between refills.
Remember too that you can accidentally wash organic matter from your planter down into the rez if you top water too often or with too large an amount. Organic material leeches into rez from planter and then 'goes off'. Its always important for SIPPERS to give their rez a sniff now and then. I top water a bacterial brew weekly into a 7-gallon SIP planter but I limit it to max 1 litre/quart and I make sure to pour slowly.
The last point would be regarding outdoor temps and that sun beating down on your plastic SIP tub (often black)... I grow veg in 27 gal black plastic totes outside, like 12 of 'em, prob more this year, and I use burlap or any cloth hanging loosely from sides, or side, and this takes the brunt, maintaining acceptable temps even in all-day direct sun. Hanging loosely works better than painted-on lighter colours or even glued-on reflective materials because it cant physically transfer the temps where not actually touching the container side and the air layer between insulates. Plus, its way easier and way cheaper. Any old fabric from the Sally-Ann can be repurposed here. Good luck, Scoobs, and say hi to Shaggy. Oh, and if it interests you, keep me updated m8!
