I need to fill mine with water and leave it for 4-5 days (the plant won't be ready for 10 days or so. I'm worried about the water temp the res will get to, so will test first. Its in direct sun for 3-4 hours a day and its hot AF here every day 24 hours. A skirt is going on for sure maybe a water chiller hopefully made from an old ice machine, if I do that was thinking why not add a bubbler as well keep that res fresh, I have a spare.
My experiences so far that relate to Nick's concerns and comments are below. Although I hunt all the other forums for SIP journals and everywhere else online, I'm really doing a lot of this 'by feel' and hope you will too. On this thread I'm just sharing my experiences thus far. Sometimes curt wording can make these things sound like do and don'ts, or make someone sound like more of an authority than they mean to. I just don't have enough years of SIPPing yet to be that guy. I've got a few years in, but it'll take a few more just to satisfy my main curiosities.
So, in my tinkerings, I found that a loosely draped, light-coloured fabric, even as simple as an old bedsheet, with a
significant airspace maintained between SIP and fabric, works better to reduce temps than does reflective mylar-type plastic when physically attached with an adhesive (I had some left-over from my tree-planting days - many moons ago).
I've done comparison tests indoors and out and the difference is quite clear, usually a matter of 8-10 degrees C soil temp measured 6 inches down and close to the pot inner surface. That's draped fabric vs. no protection. The difference between mylar and fabric was 6-7 deg C. Results surprised me initially but were quite understandable, insulative values are about trapped airspace.
For outdoors, concerns about the reverse - that is, preventing temperatures from dropping below desired levels during cool nights, which is essentially the task of maintaining as steady a temp as possible day/night, I found that a thicker fabric with tight weave worked best.
It's not as cool looking as dressing your SIP like a space satellite covered in mylar, but that airspace between fabric and pot is the real insulator. Actually, cardboard, I actually really like using it - you can drop a larger box over the SIP, cutting it so it can hinge open to access. Cardboard-only dumpsters are everywhere in the city. Pro-tip: Your local multi-plex (movie theatre) will have some sweet-sweet cardboard products in theirs. This can be a very good resource for sooo many things.
Also super important is to use a light-coloured mulching or covering material spread thick. It keeps the soil from overheating but also traps warmth within overnight, levelling out temps. I happened to find some old furniture that had rough cotton as stuffing and it has been ideal. But a couple inches of lightly coloured leaves or even synthetic materials will do the job.
You won't have water temp/dissolved O2 problems in the rez provided your SIP is functioning, ie wicking. I run some pretty big integral reservoirs, 10 gallons, but the SIPs use it fast, such that it doesn't sit long enough to get anaerobic,
but if you use any animal manures beside frass or EWC, well, just don't, nitrogen soup easily results if it leaches.
Not to say I don't tinker, I have two 27-gal tote SIPs running in my 5x5 right now with small aquarium air pumps bubbling away in the reservoirs (6gal) on burst timers 5min on, 15min off. These reservoirs are fertigated with M3gaCr0p and Sweet Candy, in 0-10ppm tap water (chemically dechlored). I check the PPMs and pH less frequently than I used to but still enough to keep an eye on and hopefully, keep learning. I don't see significant pH change with these small pumps and air stones on timer settings like these when using these ferts, or with plain water when doing organic EWC-fert'd SIPs.
With other ferts (GH Flora and Maxi) and using much bigger pumps (30w) I did get pH swings. Ultimately the pH change impact on the crop was still negligible to nil in my estimation, but only because the peat/perlite-based Promix and SSM#4 I use for fertigated SIPs are very well buffered, as is my custom 'organic soil', so your mileage may vary on pH.
Remember, ultimately, the matrix sets pH, and the reason hydro-growers must monitor so closely is that they have no matrix. Nonetheless, I feel that extremes and big swings should be avoided, so I do.
Briefly, I'm reminded that there's an awesome mixed calcium source (OMRI cert) product made in Pac NW USA called Dolopril that I recommend, highly - it is so cheap and so good! It's just a few different organic calcium sources, pelletized, that dissolve on contact with moisture. It just seems to work quickly, provides lots of calc and buffers really well, and I like a convenient multi-source that's so easy to work with and flexible. It's a brix machine, grapes look awesome this year!
BTW, I'm starting to see inexpensive DO meters pop up on AliBabba.... these have been extremely expensive up to now.
Live long and prosper!
this part is a water reservoir with supports and an overflow pipe... 
rofl
