My buddy bought an Accurate 8 meter to test aside mine. When inserted into the same hole at various pH levels the two meters were within 0.2 pH units. Of course both could be wrong but the readings make sense relative to plant responses. Recently I tried blood meal for the first time on some potted blueberries. About a week later I took pH readings just to monitor things. At first I thought the meter was off because readings were high. But now I think the blood meal raised pH. After switching back to ammonium sulfate the pH is now back to the 4.5-5 I want. So I'm still pleased and think the meter has already paid for itself.

A good soil testing lab. The cost of testing by a good lab ranges from about $6.00 per sample to $50.00 per sample but will provide you with more, and much better, information than something that reacts with a reagent or relys on sending a small electric charge through the soil.

Should have posted this sooner but here is a reply I got back from an inquiry - Thank you for your interest in the National Center for Home Food Preservation. Regarding your question: (My sent message) Background, I am a home food preservationist with an extensive history of home sausage making (both with hot ((refrigeration required)) and some cold smoking ((humidity and temperature controlled to produce country cured sausage, no refrigeration required)), home canning (pressure canning only, I do not trust water bath under any circumstances) and extensive dehydrating experience. I have done a little pickling under the recommendations that the USDA has out in regards to fish and hardboiled eggs (including the need for refrigeration). However in my research into historic preservation techniques I have found references to pickling (especially) fish preserved at room temperature. The references also stated that the vinegar solution used at the time was homemade and was of strength higher then the present 5% available for modern commercial sales. Given that botulism spores growth is inhibited at a PH of 4.6 and they can not therefore produce the toxins, the fact that! a 10% or 15% acetic acid can be readily produced using food safe glacial acetic acid (99.85% available commercially mixed in proper ratio with water (yes, acid to water, I remember basic chemistry) and the PH of the 10% solution is approximately 2.4 and given that 1.5â x 1.5â x 0.75â pieces of fish would readily equalize PH is this theoretically a safe preservation method. Please do not give me the standard rely of not recommended or approved due to lack of experimental data etc. brush off, I am just looking for a theoretical answer. (The reply) This is Elizabeth Andress, Director of the National Center. I personally apologize for not getting back to you sooner, but we have been trying to keep up with people needing help with more standardized recommendations and methods of preserving. I can tell you that under the circumstances you describe with the low pH environments, that theoretically botulism spore germination and toxin production does not seem likely. But that is indeed as much as I can say. You would want to make sure the fish pieces get below pH 4.6 throughout fairly quickly to keep it longer at room temperature (probably at least within 24 hours). It is not a brushoff but a fact that no one here has any practical experience with pickling fish at room temperature (or for that matter, at any temperature). We do not have USDA pickling or smoking for fish on our website or in the USDA canning guide, but there is information from Oregon State University we have shared on smoking fish. I have pretty much relied on contacts in Alaska, or formerly in Oregon, for issues related to smoking and pickling of fish. You also might find an actual food microbiologist actively researching with bacteria at Univ. of Wisconsin who knows more in detail of C. bot. patterns. Thank you, Elizabeth Andress

Yeah ... lots of critical things to consider such as initial and changing pH effects*, buffering, multivalent cations, anionic and cationic micronutrients, and zeolite like ion exchange surfaces on soil particles, which make it a play day for chemistry discussions. Then the attack and breakdown of plant and animal litter to slow release nutrients brings up neat microbiology and biochemistry aspects. Material science then decides to manipulate the situation with osmotic release and diffusion of encapsulated nutrients. And hydroponic principles try to partially play nature taking over the hydrology and lighting it up. Physics kicks ideas in there on this last aspect. For instance did you know that fluorescent light indeed glow when struck by energy (as you know), but much of the light intensity flashes through a series of distinct colors at 60 times a second? * Plants cheat neatly by manipulating ion exchange release of cationic nutrients. They knock off ammonium, potassium, magnesium, calcium and other positively charged ions by producing acid(s) to knock it off. H+ alone can cause the exchange but if the acid is on a small organic base (anion) like oxalate this organic can diffuse around and pull at the cations on soil that the plant wants and help knock it off, helping in the "weathering" breakdown of soil too. Chelators made by plants and microbes make it really interesting too. They diffuse around and hold certain critical nutrients so tightly that the plant has the choice of finding more, having a deficiency (specific nutrient starving), making a stronger chelator to take it back, and/or breaking the chelator down to free the nutrient. Now the fun parts ... the plant one might be considering is not be alone. A group of similar or different roots might be working together AND competing in that patch of soil, with different players at different depths Trees cheat and certain non woody plants cheat and go low. Moles, gophers and field mice run through this soil zone toox playing their games. No soil contact then no nutrient uptake, no root then no nutrient collection there for the plant, loss of stored nutrients and need to spend energy replacing the root. And there are smaller life forms co-inhabating the soil with the roots that are also directly or indirectly effected by soil pH. Let's put them into three classes as those that (1) don't generally effect a plant much, (2) can hurt the plant, or (3) can help the plant. Let's see ... hurting a plant is bad, unless it hurts a seriously competitive plant more. Helping a plant is good, unless it's again that serious competitor. Plants are not stand alone organisms in naturem. They live in community with microorganisms. So what if the soil pH helps support the growth of a microbe that can grow all over your plants roots? Sounds bad I know, but there are those three classes mentioned above. If your microbe is a pathogen that is bad. If it doesn't attack the plant but runs out and breaks down nearby leaf litter, great free food. It it doesn't hurt your plant but by being on root surfaces can compete with and stop pathogenic microbes from getting a foothold, great a free natural inoculation for immunity. There was a company called Eden Bioscience a couple decades ago here in the PNW that made an interesting observation. In large scale evergreen seedling production for forestry sometimes there were large scale fungal blights. Sadly alot of the seedlings all died at once in mass. However, sometimes there were a few seedlings near each other that did not succumb! In fact they looked totally healthy! When isolating bacteria, yeast and filamentous fungi from the surfaces of these plants they found that certain kinds could be grown in the lab that protected seedlings from attack, when sprayed onto them. These microbes grew best in their optimal pH range. They indeed colonized the plants, in this case leaf surfaces. And their presence did protect the leaves from pathogen attack. Obviously similar things must be happening in nature in the leaf canopy and also soil root zone of plants. So when a plant likes acidic pH 5 - 6 soil, is this just because nutrients are more available it? When I went to school, in what now seems like the dark ages, most plant physiology books focused almost solely on this. Or is it because beneficial microbes helping feed or protect the plant need that pH? My firm assumption is that both chemical and microbial pH dependent effects interact to make an optimum environment for that plant. And that some plants in the natural environment survive best, rather than grow best, at their optimal pH range. Why do many fungi sour (strongly acidify) what they are busy rotting? Niether competive microbes nor does the dieing plant tissue like it. The fungus gets more. This is exactly why you want to check the pH in the soil that you might be soon preparing for your new vegetable or herb garden this spring. Too basic, your plants starve. Too acidic, the pathogenic fungi don't starve. Then like the heirloom story of The Three Bears ... there's one pH that's just right.