Greetings SIPers,
I'm planning on building my first SIP on Saturday... will post some pics and info.
Turns out I didn't have the right tubing, so I went shopping at ACE and Home Depot today.
I got a couple new 5 gal buckets, both opaque with measurement markings... thinking they'd be helpful to observe root growth and res level for these first SIPs. (I will shield them from light and heat w/ reflective bubble material.)
I realized that a 2 gal bucket would probably be perfect for the insert, so I have a couple options for that: one is the standard ACE 2-gal HDPE bucket, the other is an HDX 10-qt (2.5 gal) HDPE with measurement marks (Home Depot). These will need to be cut down to the right height, and I'm now thinking 6". (The GroBucket insert height is 7".) I was going to do 5", but I decided that the difference between 5" and 6" is really negligible in terms of soil displacement, so I'd rather have more air space w/ 6". I think the HDX 2.5 gal "mixing container" is going to work best—it's the same height as the ACE 2-gal bucket, but wider.
and the sides are more angled, which will create a bigger wicking zone.
EDIT: Scratch that last part... I don't think it's true. The HDX does have a wider rim... 1.4" wider. What's important is that when the HDX 2.5 gal bucket is reduced to 6" height, and when placed upside-down in the 5 gal bucket, it will have a more snug fit in the bottom of the bucket. The ACE 2-gal bucket fails in this regard, as it just fits exactly with its stock height of 9-3/8". When cut down to 6" height, the snug fit will be lost. ... fine points!
I found the HDPE 1-1/4" x 2 ft. black tubing at Home Depot ("IPEX polyethene pipe"), and also got a 3/4" one of those to maybe use for the drain hole. (Actually what I grabbed was a 1" in the 3/4" bin! The 1" is a bit too big for the drain tube... 3/4" would be perfect. Oh well, next time.) I also got a couple 2 ft sections of 1/2" PVC, so that will work for now for the drain.
Approx. cost of parts for one SIP, all at Home Depot...
• $7.00 for the 5 gal bucket
• $6.00 for the 2.5 gal bucket
• $1.70 for 1-1/4" watering tube*
• $0.90 for 3/4" drain tube**
* 2 ft. section, would be enough for 2 SIPs w/ slight design mod.
** 2 ft. section, enough for 4 or 5 SIPs
Total: about $16.00
This SIP is made from 100% high density polyethelene plastic (HDPE, #2), which to my knowledge is the safest plastic to come into contact with growing plants that might absorb chemicals through their roots.
I also learned today that virgin HDPE buckets are technically the same as what's sold as a "food grade" bucket. Just wash 'em out before using. A guy on Reddit said re: the standard ACE 5 gal white bucket... "Those are HDPE buckets. Generally they are food safe whether marked that way or not - the FDA considers virgin (non-recycled) HDPE food safe, while recycled HDPE is evaluated on a case by case basis."
looking forward to building this out on Sunday.