Connecting Dosatron to garden hose

[Wood]

Does anyone have advice for connecting a Dosatron D14MZ2 to a garden hose without leaking? I bought this used unit from eBay that seems to be in good shape, but it's not making a tight seal to the female end of a garden hose. I was hoping to avoid a glued-up PVC connection just for aesthetic reasons but that might be the best option

 

[Newish in Oregon]

Does anyone have advice for connecting a Dosatron D14MZ2 to a garden hose without leaking? I bought this used unit from eBay that seems to be in good shape, but it's not making a tight seal to the female end of a garden hose. I was hoping to avoid a glued-up PVC connection just for aesthetic reasons but that might be the best option

It's a little tough to see exactly what's happening [and I have no experience w/ a Dosatron] but wonder if you need a need washer for the garden hose

 

[bwaynef]

Does the Dosatron have GHT connections? If not you can buy an adapter at Lowes/Home Depot that should adapt 3/4 N/MHT to GHT. Also, Plumber's Tape.

 

[Wood]

I think the washer is still functional. The same female end of the hose works perfectly when it's connected to another hose or to the bib

 

[Wood]

Does the Dosatron have GHT connections? If not you can buy an adapter at Lowes/Home Depot that should adapt 3/4 N/MHT to GHT. Also, Plumber's Tape.

Hmm I thought it was a male GHT fitting but maybe not.

Well damn, that's almost certainly it:

Connection Size: 3/4” NPT

That's an easier fix than I expected. Thanks!

 

[pandacular]

I’m interested to hear your thoughts on the dosatron! Likely something I’ll need, but I’ve had too many bonsai outlays this season to justify it just yet.

 

[Wood]

Does the Dosatron have GHT connections? If not you can buy an adapter at Lowes/Home Depot that should adapt 3/4 N/MHT to GHT. Also, Plumber's Tape.

This worked perfectly! Two 3/4" MHT x 3/4" FIP adapters fit perfectly into the garden hose on both sides and it's in great shape. These were the adapters I used: https://www.lowes.com/pd/B-K-3-4-in-Threaded-Male-Hose-x-FIP-Adapter-Fitting/1000504869

For anyone else looking at this later, the Dosatron D14MZ2, which I think is the popular model, has NPT (national pipe thread) fittings. FIP is "female iron pipe" which is the same specification as NPT, so it should be interchangable) and fits on the Dosatron. GHT is "garden hose thread" but I only found adapters marked as MHT or FHT (i.e. male or female hose thread)

@pandacular I'm excited to use this for the season but I think after a few months I'll have a better opinion. I really struggled to beat some chlorosis last year, so I think this will help a lot. I'm trying Andrew Robson's fertilizer schedule for now, which is Miracle Gro diluted to 1-0.5-0.66 NPK. The numbers end up really convenient. Dump a 1 pound bag of Miracle Gro powder into 5 gallons of water and set the Dosatron to a 1% solution

 

[pandacular]

Are you doing any ph adjustment? That’s the real key benefit for me, as I can fertilize regularly, but have no good way to adjust pH

 

[Wood]

Not yet! I had planned on it originally but I think the fertilizer will be good enough.

My tap water was somewhere around 7.8 last fall when I originally got it. About two weeks ago, my tap water was 7.0. This weekend, it was something around 7.5. I figured I'd try fertilizer without pH correction and see how it goes

After setting it up and testing the diluted solution coming out of the hose, it was at 6.9 pH! Just fertilizer might be good enough for you too!

 

[pandacular]

Mine has been testing around 8.2

 

[Gabler]

After setting it up and testing the diluted solution coming out of the hose, it was at 6.9 pH! Just fertilizer might be good enough for you too!

Regular Miracle-Gro is very acidic in its undiluted form. I think it's probably made with municipal tap water in mind. Your mix has a perfect pH for most plants.

 

[Wood]

Makes perfect sense as a consumer product, but something I never considered. I assumed it would be just straight fertilizer and not much else. If I was manually correcting the pH I would be shooting for 6.5 but this is good enough that I won't bother now

 

[Gaitano]

I set mine up for pH adjustment as my tap is 9.5-9.8. I’m using a Newtry pump with a few extras. A filter for chlorine and have it hooked up to timers for my drip irrigation sprinklers. I haven’t run any tests yet as it’s been cold and rainy, but hopefully this weekend I’ll be able to give it a go.

 

[Gaitano]

I ran the tests today. I have a 5 gallon bucket of 9.5 ish pH tap, added 110ml of pH down which lowered the pH down to 1.3ish. I set my pump to 1% and the end result (collected at the end of my sprinkler line, 2 gallons) was 6.8ish. Success!

 

[Wood]

Did you calculate the pH down injection rates or just keep experimenting with the numbers? How'd you do the calculation?

 

[Gaitano]

I did the bucket test. I diluted 5 gallons of 9.5 down to 6.7 using 6ml of pH down.

So, you spent 6/5 = 1.2 ml of pH down per GAL.


The Newtry I have can dose between 1:500 to 1:50 = 0.2 % to 2% = 7.5ml/GAL to 75 ml/GAL

So, you need to inject 1.2 ml/GAL of acid – which is below the minimum of this injector

Then, what you need to do is you should pre-dilute the acid with water and inject it at higher rate.

A good pre-dilution will leave the new stock solution in the range (near the middle) of injection of your injector

For example, lets say that you dilute it by 30 and then you add it 30 times more

How do you dilute by 30? Well, you add 29 parts of water (cups or any other measure) and one (1) part of acid – note, always add the acid to water and not the opposite.

Then you will have a 1:30 dilution that you need to inject 30 times more than the 1.2 ml/GAL that we calculated.

That means that you need to set the injector at 30 x 1.2 = 36ml/GAL. The injector does not come graduated in ml/GAL (some do) so you use the conversion chart attached where you will see that 36 ml/GAL is almost 1%.

Now, these calculations will be close – you still need to measure the pH after you do all the application – take a large sample to measure (not a cup but a bucket). I collected 2 gallons and tested it.