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Gritty Mix and 5-1-1 mix

Posted by blazeaglory 10 SZ22 OC Ca (My Page) on
Sun, Jul 8, 12 at 23:28

Hello. I was wondering. My water Ph is very high (7.8). Are the mixes I mentioned Ph neutral? Compared to a regular "MG" mix would my plants be solely reliant on the Ph of my water for nutrient uptake or will the gritty mix and 511 mix Ph fluctuate over time with watering? You know what I mean? I do plan on adjusting my Ph but for this question I will use my starting Ph of 7.8. I plan on potting some dwarf citrus and am really interested in these mixes. Thank you.


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RE: Gritty Mix and 5-1-1 mix

Am I reading that correctly - you are in Orange County, CA, right?

If so and you're using county water then your water quality looks great to me. If I'm looking at the right report (see here) then you have pH ~8 with ~16 ppm of Mg and ~48 ppm of Ca and total alkalinity of ~120 (180 as CaCO3 equiv). Your alkalinity is on the high side but the rest of the report looks great (for plants, I wouldn't drink it).

1 tsp of FP in 1 gallon of water will give you ~6 ppm of Mg and ~25 ppm of Ca. I mention this because your water has a good ratio of Ca:Mg and it already has both in higher levels than you'd get with typical usage of the liquid fertilizer most people around here talk about.

To answer your question directly: no. The mixes are not neutral. The gritty mix will be closer to 7 than the 5-1-1 (which will be more acidic) but *it doesn't matter.* The pH of your mix initially has very little to do with the pH levels your mix will maintain over time. In containers the soil pH will be determined mostly by the pH and alkalinity of the water you use and by the type of fertilizer you use and its ratio of ammonium to nitrate (*and* the rate at which the plant is taking up both of those nutrients which can vary depending on temperature, cultivar, etc).

You should basically assume that the initial pH of the mix itself is of no consequence when it comes to determining the pH of your soil over the long term. You do need to pay attention to the initial pH but only because if you transplant something into the mix you want the roots to function reasonably well from the get-go. All this means is that you need to raise the pH of the bark or peat slightly so they are more friendly to transplants - the directions for doing that are built into the 5-1-1.

I grow citrus trees in both mixes. Either will work for you and there are pluses and minuses to both. In terms of pH and nutrient availability you will find that the 5-1-1 is slightly more forgiving than the gritty mix. At your pH and alkalinity if you grow citrus trees in containers you will almost certainly develop Mn and Zn deficiency even if you use something like FP (which, again: you do not need to do based on your water quality). You could avoid this by acidulating your water or by using foliar applications of Manganase Sulfate and Zinc Sulfate (1.5 g per gallon and 1 g per gallon respectively - they can be mixed and applied to new growth on plants showing deficiencies).

Just looking again at your water report you also have adequate/luxury levels of B, S, Cl, Na, & Cu. Nickel will be in your soil via the bark and or peat and you likely don't need to add any.

All your water may be missing is: Mo, Zn, Mn, & Fe. Were I you I would use a straight 5-1-3 fertilizer and then manage the micros as needed myself. You will find it much cheaper than the usual suggestion. You could also go with Jack's Professional 25-5-15 High Performance and you wouldn't have to manage your micros as often (you will still get Zn and Mn deficiency at your pH unless you acidulate or use a serious acid reaction fertilizer - but then you will blow your NPK ratios).

The cheapest and easiest option would be to use the Jack's (or another 5-1-3 with Mo and Fe) and then use the foliar sprays 1-3 times a year.

If you acidulate your water I wouldn't use sulfuric - you have a ton of S in there already. Maybe citric or vinegar (don't use phosphoric, nitric is dangerous). This will be moderately expensive and moderately time consuming even with a chemical injector.

Do yourself a favor and avoid the expense of Foliage Pro with your water. You will be correcting micro issues in any case and you have better Ca/Mg/S than the fertilizer can offer you anyway.


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RE: Gritty Mix and 5-1-1 mix

I said "per gallon" above for the foliar sprays when I meant "per liter."


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RE: Gritty Mix and 5-1-1 mix

Very interesting information. Where did you get that water report? Initially we (in Westminster OC CA) get our water (roughly %75 of it I think) from the OC district that is in control of the aquifer in Northern OC and the rest (about %30) from the Colorado river I think. After my city of Westminster gets the water they add alot of chlorine and chloromine. I dont know if they take anything out or not. When I get the water its exactly 7.8Ph and when it dries on the dirt you can see the calcium deposit. Other than that we have excellent water and I think Westminster won alot of first place awards in OC for best tasting tap water. I dont know any of the other levels but I can check on my cities website or call the guy who is in charge (I found his number one day).

I do have a bottle of good micro nutrients but as for a base macro formula I have 3-1-2 miracle grow and ALOT of 20-20-20 with micros. I also have a few different shultz liquid with high P ratio and I dont think Ill use them. I am going to use about a half cup of vinegar (apple cider) per gallon of water to bring the ph down a bit.

I was reading though that my climate gets pretty hot so I think Im going to make another mix as well with more of my native soil (sandy loam) and peat, perlite maybe some smaller pine bark so I dont have to water as much.

Thank you for the good info:-)


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