Masterblend 4-18-38 question for tomatoes in potting mix
 

I've read quite a lot (and watched videos) of this fertilizer for hydroponics. What I haven't seen answered, though, is exactly how to use it for tomatoes in pots (2'x4' boxes, and half-barrels...big pots). I understand the mixing process of the three components - don't pre-mix, use exact measurements, add the calcium nitrate last, etc. But how is it used for containers? Do I use it weekly, daily, exclusively, a little per plant daily and then finish watering with non-fertilizer water?


I have seven 2'x4' boxes on my deck that will have two tomatoes each, and about 10 other large (half-barrels) containers for tomatoes. Plus some more containers for peppers, zucchini, etc. MG potting mix with some small pine bark mulch mixed in. Have been fairly successful for several years, but this is the first time I'll be using the 4-18-38 fertilizer/calcium nitrate/epsom salt.



Thank you.

[QUOTE=LoriA;763648]I've read quite a lot (and watched videos) of this fertilizer for hydroponics. What I haven't seen answered, though, is exactly how to use it for tomatoes in pots (2'x4' boxes, and half-barrels...big pots). I understand the mixing process of the three components - don't pre-mix, use exact measurements, add the calcium nitrate last, etc. But how is it used for containers? Do I use it weekly, daily, exclusively, a little per plant daily and then finish watering with non-fertilizer water?


I have seven 2'x4' boxes on my deck that will have two tomatoes each, and about 10 other large (half-barrels) containers for tomatoes. Plus some more containers for peppers, zucchini, etc. MG potting mix with some small pine bark mulch mixed in. Have been fairly successful for several years, but this is the first time I'll be using the 4-18-38 fertilizer/calcium nitrate/epsom salt.



Thank you.[/QUOTE]
I have used it for several years as continuous feed. I think the best instructions are on Hydrogardens website. Look for the tomato formula and scroll down until you find the instructions. Good stuff, it's The Sauce.

Aloha,
Yes, it is the sauce.
I'm using it for almost 3 yrs in a coco, hydroton mix in totes, pots and a NFT rail for lettuce.
I've tried a few liquid 3 part brands, no contest. If you havent seen MHPgardener on youtube check it out. I'm guessing you have. Check your waters ph and mix correctly. One thing I found is to mix MB with the epsom salts then in a seperate container mix calcium nitrate then combine. That way they all get dissolved . Just some info. Amazon sells it in many sizes.
Aloha,
Tom

yes, I've seen the YouTube videos. But everything is geared towards hydroponics, when I'm using potting mix in extra-large pots and boxes on my deck. Tom, do you use it every time you water (daily +) in potting mix?

Pardon me for jumping in as I'm NOT Tom but I use it in 15 gal. grow bags filled with ProMix. They get "the sauce" every watering which in the hottest months is twice daily.

Dan

Aloha,
I do usually use everytime. But if I just want to give a quick splash until I get time to mix a batch. I do that on occaision. Please note that this became very useful for me because of my different ways I grow(NFT, Kratky ,coco coir & recently inground)
Enjoy, Tom

I'm also trying my best to use 4-18-38 in my garden. I'm trying to mix up a concentrated solution to go in an EZ Flo tank fertilizer injector to mix into the drip irrigation system. Despite adding the components in order and thoroughly mixing before each step, it seems to be coming out of solution when I add the CalNitrate.

Does anyone have experience making a 4-18-38 / Magnesium Sulfate / CalNitrate concentrated liquid and advice for this situation? How high a concentration were you able to mix where it would stay in solution?

I'm very interested in this subject:yes: I'm doing Kratky plus inground growing this year. I'm wheelchair bound with some limitations and I don't like constantly weighing out and mixing the masterblend chemicals. So, to make things easier for me, I did some "calculations" :shock: to come up with the maximum concentrations I could get of MB part A (MB plus Epsom Salt) and B (Calcium Nitrate) and then optimizing these amounts so that I would have a convenient dosage rate. (Actually part B wasn't really a concern as it's so much more soluble than the part A components).

(I can show you how I came up with my results, but as someone on another forum somewhat rudely told me "just because you can do calculations doesn't mean you should." :dizzy::))).

Anyway, here's what I came up with and so far it's working for me in my situation:

For 500 ml each use 120 g MB and 60 g ES for A and use 120 Calcium Nitrate for B

Keeping in mind that the chemical bulk displaces some of the water volume, you don't use a full 500 ml water for each part. Here's how I mix mine (it can of course be scaled up or down but I find the water bottles convenient for me at this stage of my garden):

Label 2 empty 500 ml water bottles A and B
Using a funnel, add 120 g MB and 60 g ES to bottle A
Fill with water to about an inch of the top and shake to dissolve chemicals
Using a funnel, add 120 g Calcium Nitrate to bottle B
Fill with water to about an inch of the top and shake to dissolve chemicals

Use 10 ml part A and 10 ml part B per gallon of working solution.

Depending on what I'm growing, I can adjust the dosage up or down a bit. I've had no problems combining parts A and B shortly before adding them to my reservoirs or jugs of water. You could do some experiments with different times and temps to see how long everything will stay in suspension. I've also been able to add about 10% pH Down (whats generally required for my tap water) to the combined concentrated chemicals without any dropout.

I should say my little formula hasn't been confirmed by anyone "official" or more experienced, but it works for me. Not sure about how the EZ Flo works, but hopefully this might be a starting point for you.

IF I'M WRONG ABOUT ANY OF THIS :oops: PLEASE CORRECT ME!!!

Anne

[QUOTE=aclum;764264]

Use 10 ml part A and 10 ml part B per gallon of working solution.

[/QUOTE]

Anne, this is consistent with the response I also just got from the manufacturer. It seems that a concentrated 3-part solution isn't possible without falling out of solution, so Part A and Part B need to be injected separately, or only mixed into a diluted solution to start with.

Here's what the manufacturer said:

[I]The issue here is that you cannot include the Calcium Nitrate in a concentrated solution with the other components. Most growers using these products either use two injectors or one injector with two ports. Part A would be the 4-18-38 and the Magnesium Sulfate, Part B would be the Calcium Nitrate.[/I]

Based on this I'm going to go to dual injectors for my garden.

Thanks! That's interesting - I'll have to look into the EZ Flo system. Can they be used with drip soaker hose or just drip with individual emitters?

It would depend on the flow rate. I think the EZ Flo has some challenges when you get to very low flow rates, and can't be below 7.5 gph, so that would be the thing to look at. It's also a bit expensive to setup two of them for this purpose since you can't mix the concentrates.

Post the results if you figure out a system that works with the affordable injectors? Whatever you figure out don't forget the third injector for pH, or maybe a fourth for another crop with different needs in the same location. lol

I went ahead with using two EZ-Flo 1010-HB units. The low pressure version could probably also work, but I picked these because they seem more durable. It is designed to connect inline with a garden hose, so I’ve simply put two of them in series ahead of my drip line. One reservoir gets Masterblend + Mag Sulfate, the other reservoir gets the Cal Nitrate. The first 1 gallon tank has 16 oz Masterblend + 8 oz Mag Sulfate, the other one is 16 oz Cal Nitrate. I set both to the same feed rate and adjust until my desired EC out of the drip system.

It seems to have worked out well so far, with a couple things that do need to be sorted. I’m assuming setting both tanks to the same feed rate is close enough, but ideally I would like to know the independent EC for the first and second to calibrate them independently. Im just measuring total EC and it’s possible the part A solution is feeding at a different rate than part B. Good enough for my purposes I think.

The second thing I’m waiting to observe is how the system gets diluted over time. I’ll have to periodically measure EC. EZ Flo says the fertilizer sinks to the bottom and the added water volume stays at the top to keep concentrations relatively even over time. This is counter to my understanding of how fully water soluble nutrients would behave though, so I expect to have to turn up the feed rate over time until it needs to be refilled.

Mark, I have not made any effort to adjust for pH. Any sense how important this is for the home gardener? Peak yield isn’t so important to me, I’m very happy with a simply very productive plant.

[QUOTE=dshreter;764292]Mark, I have not made any effort to adjust for pH. Any sense how important this is for the home gardener? Peak yield isn’t so important to me, I’m very happy with a simply very productive plant.[/QUOTE]

Well that depends on the situation at that particular home gardeners location. About 80 miles North of me people have a soil pH of about a 4.5, so you tell me? I have water that runs a 8.3 in my area, again... for good results what are the requirements?

You would be surprised at the knowledge and dedication that the average home gardener has when they want results, I see thousands every year. At any rate, enjoy, sounds like you have it handled.

No, I don’t have it in hand! pH is around 8 here, and I grow in Pro Mix HP. What would I be targeting as optimal?

[QUOTE=dshreter;764307]No, I don’t have it in hand! pH is around 8 here, and I grow in Pro Mix HP. What would I be targeting as optimal?[/QUOTE]

The fertilizer itself with the correct blends of N can lower pH on its own, if the tap water is not too basic that alone can be enough for some. We have to use acid on top of that. I use 55 percent Phosphoric acid, it does not affect antagonism or cause any precipitation with Ca and S. We shoot for a 6.5 when growing seedling and a 6.2 with mature plants.

Many don't know, but we just don't grow tomatoes, we have a large retail center. We have several thousand people come through every year, we do sessions with the state Master Gardeners programs, we do tours, and have an information center where people can learn. We are a full service GH and setting up home hobby growers is what we do, weather it be organic twists or synthetics in containers. We are also in a huge loop, we can call or send samples to labs, I have white coat support everywhere, we are also under scrutiny of the USDA, DEC, EPA, etc, etc. In short, T's crossed I's dotted daily, and we try to pass along high value information so people are successful and HAPPY. The last three words all go together.

In short you can add pH down to your fert tank, I put mine by itself.

You are a wealth of information, I’ve made a lot of my own plans based upon your grow threads! Do you measure your pH from runoff to account fir the medium or the fetigation solution? I’m growing in mostly peat which I understand is acidic, so I assume needs to be factored in?

[QUOTE=dshreter;764323]You are a wealth of information, I’ve made a lot of my own plans based upon your grow threads! Do you measure your pH from runoff to account fir the medium or the fetigation solution? I’m growing in mostly peat which I understand is acidic, so I assume needs to be factored in?[/QUOTE]

We just pass on information, others figure this stuff out first. lol I measure what goes in, and I also have a soil stab that I use more for flowers like Geraniums. You will water very often, largely we control our issues with that. The farmer who has thousands of acres cannot do that, he uses different blends of N to control pH with his fertilizer. We have tomatoes in containers from March to late October and they are mostly same consistent if you leach out a tiny bit. It's a long season in a container and we are not seeing much drift.

Keep us posted on your results, enjoy the season.

AK Mark. I did soil tests myself with a Environmental Concepts test kit this spring. According to it, I am N depleted, P sufficient, and K off the chart (I'm I'm reading the K test right) PH at 7-7.5. Other than a dump of AMS (which I did at .5#/100 sq ft.) what would you recommend?

[QUOTE=D.J. Wolf;764327]AK Mark. I did soil tests myself with a Environmental Concepts test kit this spring. According to it, I am N depleted, P sufficient, and K off the chart (I'm I'm reading the K test right) PH at 7-7.5. Other than a dump of AMS (which I did at .5#/100 sq ft.) what would you recommend?[/QUOTE]

This is really helpful in your case. When we have to piece stuff together out comes the general use, or we dial back whatever everyone else is using and use observation from there. So we know K is the most important, (for the tomato plant) P is immobile in soil, no N per say, second most important, and you need some secondary nutrients in there.

If it were me, I would add Blood Meal and Fish Bone Meal or Seabird Guano and would still add some K/ Langbenite, which has MgSO4 in it too.

I would also be tempted to use our 4-18-38 mix once a week for another method, and would use observation as a guide for further application.

Last would be a general use or very dialed back whatever and observation again, notes are helpful too.

I tell people often that we stumble forward, that's how we learn the best.

Good luck, tomatoes are hard to burn up, they are also pretty forgiving.

[url]https://nrcca.cals.cornell.edu/nutrient/CA2/CA2_SoftChalk/CA2_print.html[/url]

[QUOTE=dshreter;764323]Do you measure your pH from runoff to account fir the medium or the fetigation solution? I’m growing in mostly peat which I understand is acidic, so I assume needs to be factored in?[/QUOTE]
You are not growing in peat moss, but in a mix based on peat moss. The pH of that mix is probably somewhere around 6. You should definitely do at least some runoff measurements to see how off they are. The more runoff, the closer they will be. The pH of the water is not that important, but the carbonate content, that will mostly dictate what direction your rootzone pH will go to.

Also, a stock solution with calcium nitrate should definitely possible, texas tomato food has a good amount of calcium nitrate in it, not sure what the trick is though.

AK Mark - How much liquid masterblend, epsom salt, and calcium nitrate mix would you feed a plant in a 10 gal container per day? 1/2 gallon per day too little/too much?

I'm not AKMark, but you should water to the plant's water requirements. I believe he has recommended that he feeds during almost every watering.

[QUOTE=grassroots159;764475]AK Mark - How much liquid masterblend, epsom salt, and calcium nitrate mix would you feed a plant in a 10 gal container per day? 1/2 gallon per day too little/too much?[/QUOTE]

How big is the plant, how warm is the weather, sunny or cloudy, what cultivar, etc, etc? You water when the plants need it. I water three times a day right now, but it has been warm. Use observation to decide frequency, the rest is noted.