I like the aeration in the top right pic. I usually pump up into a pvc manifold spraying down into the water, but any water movement gets the job done. Do your roots grow into the pump?

There are a ton of paste tomato varieties besides the basic roma that you might like. San Marzano is popular; so is Amish Paste. I had good luck last year with a hybrid roma called Pompeii. They come in different colors, too. This year for the first time I have Green Sausage, Cream Sausage, Banana Fingers and Purple Russian.

Well I just transplanted them on Saturday, so the roots aren't a problem yet. Last year I occasionally had a problem with roots jamming the pump. The pump in that picture has a small cover over the inlet so I'm hoping it won't be a problem. Only time will tell.

I plugged in a couple of mainfolds but the flow was too great. They shot the water about 20 inches in each directions (holes on more than one side). I figure I'll leave it as shown until the roots get into the nutrient, then turn the "T" 180 ° so they don't continue to directly spray the net pot.
Roma wasn't really my choice. My girls were given the plants at a library activity. In fact that whole box was a quick fix to grow them in. I have some slicing tomatoes I'm going to put into my trash can system. I just ran out of time to do it.

Looks good Grizz,
Give it a month and the tubs and troughs will vanish under the greenery :)

Sorry to be in a couple month old thread, I'm up to messing with fertilizers think this DWC fountain system version is pretty cool. Is that anhydrous Calcium Nitrate in the formula that brings you way up to what must be a calculated 886 ppm? Since the ratio of 15:11 is 886/650, all that extra calcium isn't coming from the water so it sounds like its basically in RO or D.I. water?
Thanks

I think I figured out where I was confused about your fertilizer formulation from the pic you uploaded for the snow peas and other stuff.

Looks like the hydrated Ammonium Calcium Nitrate is being labeled inaccurately by the suppliers as "Calcium Nitrate", so that is what you used, but the label from the S. Ag mfgr of the 5-11-26 fertilizer mix is confusing to me since it looks to me like the P=11 is according to "NPK" but the K=26 is not. My respects, the sole three source suppliers I can google for nute powder mixes are not very helpful, for example the 5-11-26 Chem-Gro mix from hydro-gardens.com is kind enough to put the chemical formula of CaNO3, but not only is the chemical formula unbalanced, it is also turns out to be the ammonium stuff, not even Ca(NO3)2 or Ca(NO3)2*4H2O. In this case the 886 ppm seems like a calculation or was it just a measurement from a ppm meter? For example, sulfur is in the form of sulfate is not mentioned on the mixing label by the manufacturer, so would it be included in the 886 ppm, and as S (or maybe even SO4--)?

:-? :-?

I'm asking because it's time to swallow ordering $50-$100 of nutes tomorrow and this 5-11-26 from one of the big three seems a good bet and is sold to us little guys, I would like to use Griz's nute formula so kindly provided since it is the only one I see I'm sure could do peas.

SoutherAg will sell you the 5-11-26 directly. When I calculated the ppm, I simply use the percentages provided on the label. if you visit their site and download their catalog, it lists the percentages that mix. I can't speak to your calcium nitrate question as the bag in not with me at the moment.
those numbers were all calculated with a spreadsheet. I then test the EC to have a relative scale for when I check it again.
You have to remember the P and K will be less than what is listed because the listing is a percentage of P2O5 and K2O respectively. download a periodic table to get the relative equivalents of each. something like .85 and .41, I believe.
If you live in or near a decent sized city, buy your bulk chemicals from a landscape or greenhouse supplier. SoutherAg is located in Florida (as well as NC) so, if they don't have it on hand, can probably get it for you fairly quickly.

Thanks again grizz, don't worry on my account about the Calcium nitrate labeling, I've ODed on Google to see that basically almost all the Calcium nitrate is really the combination ammoniated salt, (N~14.3+N~1.2==>"N=15.5", Ca~19), even "Yara" brand which seems to be a favorite for the no-residue soluble ingredient among some Hydroponic gurus. It is not pure tetrahydrated Ca(NO3)2, (N~11.9, Ca~16.9) which for some reason I can't find or even price. The pure tetrahydrate is the ingredient specifically mentioned for hydroponics by Howard Resh, and solubility info in chemical handbooks supports that the latter is far more soluble in cool water solution. Still, both are quite soluble and there is some thought that Ammoniated N-source, even this relatively small amount in the misleading labeled "Calcium nitrate" is not an optimal plant nutritional source and we might be better off without it in hydroponics.

I have no idea whether this ammoniated comment is just heresay which is rife, or what exactly underlies it. Most commercial field operations use high rations of ammoniated fertilizers but whether this translates to (my suspicion=actually too hydroscopic for gross handling in powder), plant nutrition, economics, or speed of release after application, or breakdown by microorganisms and secondary availability, etc., etc., no clue. But the comments are out there and it would be nice to nail down what if anything is going on here.

You know I am a rank greenhorn, and am very glad you and a few others are so happy to help us here. I didn't mean to hijack this thread, to take away in any way about your great simplified systems, but the thread was old by now and there was the fertilizer info which you volunteered that was extremely useful for a guy starting out in a practical sense, and besides the mhgardiner videos I found it a way to get some confidence about what to feed my peas. I called SouthernAg yesterday, fyi, the main FL number, and they would not ship 'oxidizers' to me whether the 5-11-26, or other individual trace salt sources; said to get it from their distributors which they don't have in my area. I found a distributor easily willing to ship and ordered it though.

In my case I'm a chemist by training which may be more of a curse than helpful at this point ;-). But I think I'll really get into playing with nutrient formulas. Too bad it is hard to do that with all the mix I bought (increases are easy for individual elements, but not decreases). For example peas are copper sensitive, so wouldn't it be fun to do a few trials...

I don't think you exactly followed the label for mixing instructions for the basic hydroponic mix on the 5-11-26, but would need to go over it to be sure. Seemed t least that your epsom salt was low if I recall right. As for the question on the NPK, yes I am considering the P&K adjustments and I was able to make my own spreadsheet to tweak formulas. As a matter of fact that is how I got flustered a bit in the Calcium nitrate question since I based everything on chemical formula and the Calcium clearly did not match the ppm's in SouthernAg's hydro mix if you follow their mixing instructions. As for the potassium, as soon as the OD passes on this I'll review it and the guy I called said he'd be happy to look at my K ppm number and hopefully tell me why it is inconsistent with their label when everything else matched perfectly.

I know this may be boring to many people, who have fertilizers that work and don't even worry beyond their favorite mix proportions. But here we are mixing our own fertilizers for pennies per refill, and others are selling this ridiculous expensive supercharged solutions they claim for twenty times more money plus shipping 90% of water all over the country, so one example question I have is perhaps the expensive mixes just do little things to make them have an edge, like put tetrahydrate of Calcium nitrate only, instead of the bulk ammoniated stuff, if that really is better (???). Since they are selling solutions, there is no hydroscopic problem. Anyway once again thanks (see what a little blurred jpg on fertilizer data can do to some of us!) I suspect my first dwc is going to borrow more than one of your ideas if you don't mind!

This post was edited by PupillaCharites on Sat, Jul 6, 13 at 13:08

I don't mind.
I don't mix per the label recipe. I simply use the provided percentages off the bag and adjust as I see fit.
Your problem finding tetrahydrate vs ammonical might be availabilitiy. I'm not a chemist so you would better know than I, but several years ago one (or more) form of nitrogen was banned from fertilizers because of the ease with which it could be converted to make a bomb. Well it wasn't banned so much as highly regulated. Maybe that is why the ammonical variety is predominantly the only one available.

Great - regarding your aluminum foil wrapped styrofoam covers, I really want to 'borrow' that idea, but with the salts in the nutrient solution I get the willies thinking aluminum will go into solution and admit I'm aluminophobic when it comes to eating - no aluminum pots, etc.

Do you put the aluminum foil completely around your improvised covers in in the dwc project and notice even the slightest corrosion, and even if you do, could you just put it around the lip and deal with bare styrofoam above the solution inside?

As for the explosive nature of nitrates, *sigh* I think it's actually the other way around and that the more energetic of the two is ammonium nitrate, and the calcium ammonium nitrate we are getting for fertilizer (15.5-0-0) is somewhat more reactive that plain anhydrous calcium nitrate (17.1-0-0). I recall hearing plain ammonium nitrate was banned unless you were a certified land-farmer on a strict need-to-use basis after the tradgedy in OK, so that's probably what you're remembering.

A wild guess is calcium nitrate tetrahydrate is actually the least risky proposition to sell to the general public of them all. Being a chemist doesn't make me know any more than the next guy regarding destructive applications of these products. We'd need some miners or a Bruce Willis out of the movie Armageddon to tell us about that.

If it isn't one thing it's another ... as a chemist without a chemical company, some states are making us even fill out red tape to buy beakers and glassware shipped to a residence ... meth scares, lunitic scares, pot scares... Add my new hydroponics' interest ... Suspicious and intrusive minds are continually judging old-fashioned fun with such negative overtones it's disheartening the way the country has evolved *sigh*.

EDIT: And there is the Al ion effect on plant roots, too:
"Larsen explained that a root tip has a "quiescent center" that houses stem cells ��" master cells, maintained throughout the life of the root, that develop into cell types and tissues. Aluminum toxicity results in the loss of these stem cells, and consequently cell division, bringing growth to a halt."

ref:
http://phys.org/news142170971.html

This post was edited by PupillaCharites on Sun, Jul 7, 13 at 14:36