Injecting Si And Preventing Lockout

[MediNice]

To keep it short, does anyone know how well Dosatron injectors mix a solution without incorporating mixing chambers?

I recently purchased 4 injectors and 2 mixers, but am skeptical that the 2 mixers will provide adequate mixing before the next injector downstream. This system is tankless and all inline.

Originally designed as such for liquid store bought nitrients:

Part A>mixer>Part B>Supplement>pH Adjuster>mixer>EC/pH meter.

However, now that I will be mixing my own recipes I would like to do the following:

Silicon>Part A>Part B>pH Adjuster

So the dilemma is, do I need a mixer after the silicon, another after part A, and another after The pH adjuster? If so, I will have to fork out some more loot and wait for the part to get here.

Does anyone have any advice on this? Thanks in advance.

 

[Fresh Starts]

You want your PH adjuster to be first injector- swing the PH before salts make it into the mix will help stop unwanted salt reactions. Some thing like this: Ph adjuster>silicon> PartA> Part B> mixer> inline Ec/Ph Meter.

Mixing silicon ahead of other salts and after the Ph adjuster is a good idea since silicon does not play nice with other salts in high concentration. The Dosatron injectors have a slight mixing property built into them already and will dilute silicon enough to avoid reaction. Placing mixers in between part A and part B would be redundant.

If you are tankless, be sure to place a back flow preventer on the incoming water source so not to pollute the water supply.

Just my two pennies.

 

[Herb Forester]

How does that work with silicon after the pH controller? Seems like it defeats the purpose.

 

[Fresh Starts]

Are you referring to silicon raising PH negating the purpose of a separate PH adjuster? @Herb Forester

Usually a formula will account for silicon raising PH by lowering stock solution A or B so that PH will stay in a desired window.

 

[Herb Forester]

So you're adjusting source water with the controller and doing the rest manually? Or using one of the softwares to calculate alkalinity and final pH? That sounds like a waste of an expensive controller, and there can be other reactive additions besides silica (P and N acids, PeKacid, etc).

 

[Fresh Starts]

So you're adjusting source water with the controller and doing the rest manually?

By controller you mean injector? Not sure what you mean by manual operation here.

...Or using one of the softwares to calculate alkalinity and final pH? That sounds like a waste of an expensive controller, and there can be other reactive additions besides silica (P and N acids, PeKacid, etc).

Using software to balance out PH with alkalinity.. well, yeah. Definitely want a rough idea of how Ph will balance out after all salts are added to the source water. The way I've configured my system is to use a PH up product only. The use of Phosphoric acid or Nitric acid is added to my stock solutions A to drop the PH to around 4.0. I don't use it by itself. Whats been a pain lately is when source water PH changes with the seasons. Thats where the adjustable PH injector has come in handy.

 

[Herb Forester]

Manually means doing all the math and assuming stability between your checks, instead of letting the pH controller do it automatically as designed. To me your method is unneeded extra work that defeats the point of having the equipment. Time is my biggest expense, so I try not to waste it going in circles, but I know others may feel differently.

 

[MediNice]

Thanks for the replies. Several folks on here and the good folk at CHN have taught me a lot in the last month. I understand now that Si should be added before other elements and the pH brought down before adding in the other elements due to reactivity at a ph above 8.0.

So when I FINALLY set this thing up tomorrow I see it as the following unless someone could convince me otherwise

potassium silicate >
mixer >
phosphoric acid >
magnesium sulfate, potassium nitrate, potassium sulfate MKP, Zn, Mn, Mo, Bo>
mixer>
calcium nitrate, Fe, Cu, fulvic >
mixer >
Ph/EC monitor >
manifold

Fresh Starts - I see your logic in the acid first. I guess it all comes down to how well the injectors mix and how concentrated the stock tanks are. I have been reccomended a 1:128 starting concentration, but would like to get down to 1:512.

And yes, the acid is calculated by the NHU calculator to get me.to.where I need to be. However, after proofing my system with direct addition tank mixes, I need an aprx 10% higher concentration of phosphoric acid to hit my desired 5.8 than the AlkCalc suggests.

My gut feeling is to use sulfuric acid as my adjuster so I can lock in my P values consistently.

It sure would be nice to know that I could remove the mixers and free up some wall space without sacrificing potential reactions.

 

[Fresh Starts]

The mixer between stock solutions is redundant from what I see, but it can't hurt. It helps to add a bacteriostatic like food grade Sodium Benzoate to stock solutions if they are being kept for long periods of time (weeks to months). Otherwise you'll get unwanted growth in the system. That is also why adding phosphoric acid to your stock solution is a good idea- low PH makes it hard for micro organisms to thrive. It also free's up an injector. But hey, let her rip and lets see the results!

 

[MediNice]

The mixer between stock solutions is redundant from what I see, but it can't hurt. It helps to add a bacteriostatic like food grade Sodium Benzoate to stock solutions if they are being kept for long periods of time (weeks to months). Otherwise you'll get unwanted growth in the system. That is also why adding phosphoric acid to your stock solution is a good idea- low PH makes it hard for micro organisms to thrive. It also free's up an injector. But hey, let her rip and lets see the results!

Thats a good idea. I always wondered about whether stuff could grow in a solution with such high concentration. I am thinking that by adding an appropriate acid to both A and B, they might dissolve better.

My sulphate and phosphate tank seems to be having issues mixing completely. A small amount of brown sediment has formed in the bottom. Interesting thing is none of the ingredients are brown. I have yet to repeat this in batch two so hopefully it was my mistake.

Also, there seems to be a powdery substance on top of my working solution after a, b, and c are added. I believe the surface powder is coming from the Solubor (potassium sulfate) because it was the last thing to dissolve when making the stock. It took hours even at a 1:128 and 120 degree water. It looks like a very fine froth of white or gray color on the surface.

Oh the beauty of error. My plants dont look happy since the conversion and I considered dropping another 8k for a rip of my old nutrients to get me back in shape. I went into the dry salts full steam. Silly me..

I have been recommended nitric acid and sulphuric acid for the stock tanks. Does this seem like a means of helping things dissolve better? Or, would you suggest part of the phosphoric acid applied to the sulphate tank?

 

[Fresh Starts]

I've noticed that stock tanks containing potassium sulfate develop the most bacteria. I know that my source of potassium sulfate is organic which might have some thing to do with the high micro organism activity. Since I've been adding Sodium Benzoate the growth has slowed to a crawl- so I highly recommend that addition. There is also a small amount of beige/brown salt accumulation in the bottom of my potassium sulfate stock tank. Here's a heads up: if the potassium sulfate is having a hard time dissolving you may run into low potassium ppm in your fertilizer. I have definitely seen this happen in my setup. Overall I like to shoot for around 210 ppm K during full bloom. So I've been increasing my injector ratios to compensate.

As far as salt dissolving goes, it's much easier to concentrate a stock solution when the PH is low. My stock tank "A" has Cal/nitrate, Potassium Nitrate, Mg Nitrate, and micros- which are all easy to dissolve. I leave the Ph alone with that stock tank and just add Sodium Benzoate. My stock tank B has most of the hard to dissolve salts in it (MKP and potassium sulfate) and like I said before I drop the PH down to 4.0 which helps assist the dissolving process. I use phosphoric acid to drop my PH because it adds phosphorus to my profile and my stock tank B has the most problems with dissolving. You can use the other acids you listed to round out your profile but it seems to achieve an added bonus to drop PH in your potassium sulfate stock tank. I also leave a capable circulation pump down in the bottom of the 30 gal tank for a couple days to dissolve all the salts.

I also have a RO filter to remove all other dissolved ions from the source water for stock solutions. This is important in my stock tank B because it has Phosphorus in concentrate which could react with calcium from the water supply.

Submitting your new fertilizer mix to a laboratory (like JR Peters) is highly recommended so you know what you've made.

Best of luck!