This week's post will start with a bit of a digression...

We got a question this week about growing (and selling) produce that is legally allowed to be called "organic".  For those of you who aren't familiar with it, "organic" is a legal term when it involved food labeling.  You must meet a rather intensive list of requirements in order to legally sell a product as "organic".  The US Department of Agriculture has specific requirements and guidelines that must be met (and certified) before products can legally be called "organic".

If you're thinking about growing organic fruits and vegetables hydroponically, you'll probably want to know about OMRI. OMRI is the Organic Materials Review Institute.  It's a non-profit certifying body for "input products" used in certified organic production.  In simple terms, they pre-approve fertilizers and additives, so you can save yourself a lot of headaches when you go to market.

You're probably thinking to yourself, "I use a really good nutrient mix.  It's got to be organic."  However, this is often not the case.  The vast majority of hydroponic nutrients are actually not OMRI listed.  In the hopes of offering assistance, I did some research on the more common nutrients and supplements on market.

• American Agritech / Botanicare:  No products are OMRI listed.  I researched the Pure Blend Pro line, Liquid Karma, Sweet, and Cal-Mag.  This doesn't mean that their nutrients aren't good.  In fact, I like them quite a lot.  From my research, I found out that a single-step in their production process is "uncertifiable".  If one link in the chain is broken, a product cannot be certified.
• General Hydroponics: No products are OMRI listed.  I researched the FloraNova line and FloraBlend (my favorite compost tea).  It appears that part of the "refining" process used by General Hydroponics makes their products ineligible for OMRI listing.  Hydroponic nutrients need to stay "in solution" in order to be of much use to the plants.  If all the "good stuff" falls to the bottom of the reservoir, it can't help the plants.  Although I don't know the specifics of their manufacturing process, it appears that their methods of keeping nutrients in suspension break the "certification chain".  This is not a criticism.  I'd rather have a good non-listed nutrient, than a lousy listed one.
• Technaflora: Some of Technaflora's products are OMRI listed.  It's not the whole line, but Technaflora is the only one of the major manufacturers to have anything that's listed.  Technaflora has Thrive Alive B-1, B Seaweed, and Soluble Seaweed listed with OMRI.  When I spoke with a Technaflora representative, they gave similar reasons for why the whole line isn't approved.  Apparently, the requirements of hydroponic gardening make OMRI listing a pretty difficult goal.  I was pleased to see the listing.  I'd say, of all the nutrients that I use, Technaflora is the best at "staying in suspension".  They tend to "fall out" less than most other nutrients.
• Grotek: Only one product produced by Grotek is OMRI listed, their commercial Fishplus fertilizer.  I'll admit that I've never had experience with Fishplus, so I can't offer much of a comment.  However, Grotek's regular like is "organic-based".  "Organic-based" is a good thing, just not legally "organic".  Although I don't have any proof, I suspect that Grotek has the same trouble obtaining an certifiable suspension as the other manufacturers.
• Earth Juice: The entire Earth Juice line is OMRI listed.  I can't say much about Earth Juice, as I've never used anything they make.  However, if you're trying to grow an organic-certifiable crop, they appear to be your first (and only) choice, short of mixing your own nutrients from scratch.
• House & Garden (Van de Zwaan): Sadly, H&G has no product that are OMRI listed.

I'd expect that we'll start to see more nutrients that have OMRI listing in the coming years.  At this time, it appears that most manufacturers have opted to produce a product with superior operating properties, at the cost of certification.  The manufacturers put a lot of effort into not clogging our sprayers, more than is usually visible to the amateur grower.

In other news:

The new 5x5 prototype PVC garden is progressing nicely.  We've done a few refits thus far, and are pretty happy with the results.  The new larger 5x5 tube allowed us to use a standard plastic "sink drain" for our water-return.  Another part that you can easily get at Home Depot.  Another small victory.

However, the pump that we bought seems to be underpowered.  We're going to get a larger pump as soon as possible.  Our 5x5 PVC garden houses 14 plant sites.  We initially tried using an ActiveAqua PU550, but it doesn't seem to be large enough.  The jets are all "spraying", but not at the full-power that they should.  Since I'm such a fan of ActiveAqua, I'm likely going to order a PU800.   For comparison, the TurboGarden uses a more expensive Mag-Drive pump.  Thus far, the ActiveAqua pumps that I've had have been nothing but a reliable workhouse.  ActiveAqua is highly recommended.

I'll eventually post the plans for the DIY PVC garden, but I want it to work perfectly before confusing everyone.

In unrelated news... we picked up a little item this week that is both useful and inexpensive.  We usually drain our aero reservoirs by using their own pumps.  However, you're always left with a little in the bottom.  Normally, we'd remove and dump the reservoir.  However, this looks like it's a lot more convenient.  We found this battery-powered siphon at Home Depot for about $10.  It was located in the seasonal section, near the gasoline containers.  It's the perfect addition for cleaning out the last water from a reservoir during a change.

Also, I'm about half-complete with converting a plastic container from Ikea into an single-site aeroponic unit.  I'll post the product number as soon as I remember to take a picture.

As always, here's the overview photo of the week: