Compost Sprayer Questions

Discussion in 'Organic Lawn Care' started by Green Lawn, Feb 1, 2011.

  1. Green Lawn

    Green Lawn LawnSite Member
    Messages: 7

    Newbie here to organics and the forum. I have been lurking around here for a while reading and learning!! I am wanting to buy or make a CT sprayer for a few small lawns (roughly 6000sq ft). I have a few questions that I seem confused on. This will be about 25 to 40 gallon tank.

    1. I know roughly what the psi should be but what GPM should I be looking for?

    2. Whatever sprayer I buy or make I am wanting to add a 50ft hose. If it comes with a 15 hose at 60 psi, what will a 50ft hose due to the psi?

    3. And as far as pump goes, do you want a pump that runs non-stop or one the will shut off.

    4. What size hose for the sprayer? 3/8 or 1/2 ? If you go bigger hose, does the psi increase or drop?

    Looking at maybe getting one from Northern Tool but am open to any suggestions or help on this. Thanks alot for the help and look forward to contributing to this forum.
  2. Green Lawn

    Green Lawn LawnSite Member
    Messages: 7

    Anybody able to help me?
  3. Yes, I will. I'm working a show in Boston until Friday and will need to rest up on Saturday...PM me on Sunday and I'll be happy to answer your questions.
  4. Turboguy

    Turboguy LawnSite Bronze Member
    Messages: 1,972

    As long as your GPM is a little more than your nozzle size it won't make a lot of difference. The answer would depend somewhat on the gun set up you will be using. Probably 5 GPM or more will work.
    It won't change it a lot. I have all the formulas for line loss back in my office but like Peter I am up at the New England Grows show fighting off the mass of attendees we had here on opening day. Off the top of my head 10-15% loss.

    It sounds like you are thinking about a 12 V demand pump. The ones I have seen are diaphragm pumps and if you are only wanting to pump through 65' of hose they should work ok. Much more hose and you won't be happy. That isn't a lot of hose to do someones yard with but if you are only doing front lawns it might be ok.
    The half inch hose is the better choice. You will have more pressure loss and more harmful friction with the 3/8" hose.
    Good luck with your project. You are going to have some limitations but you should be able to put that together pretty cheaply. You can do an internet search for Compost Tea Sprayers and see the way some units are made.
  5. Green Lawn, one of the best things you can do is choose a sprayer which has a pump which is suitable for the job at hand.

    Our experience has taught us that diaphragm pumps are most gentle on the microbes. It's all about what comes out of the gun.

    There are other logistical issues such as aeration in the tank(s), accessibility to plumbing for cleaning, fitting configuration, strainer sizing, ability to carry undiluted compost tea with aeration and the ability to blow off chlorine on the road.

    I agree with Turboguy in that I wouldn't get too caught up with pressure loss in longer lengths of hose. 1/2" is the way to go. Basically, you want to apply from 5-7 gallons per 1,000 sf of diluted CT.

    This is a setup that has worked for us for several years;
  6. Turboguy

    Turboguy LawnSite Bronze Member
    Messages: 1,972

    I was looking at Peter's sprayers yesterday and they are very impressive and would do a great job with compost tea. I do have some differing opinions of pumps and had a discussion with his co-worker on the topic. I have worked in the sprayer field for most of my life and concentrated on equipment that sprays for the past 21 years.

    Peter likes the diaphragm pump because of the pulsating action when it pumps and that makes sense. My main concern with that style of pump even though I was part of introducing them to the American market is that while it is pumping it is briefly subjecting the microbes to pressures well beyond an acceptable limit. I think the pressures are brief enough that it is not going to be a big deal and it is a very acceptable pump to use for CT.

    My own prefference is for a centrifugal pump since it pumps with almost no contact and under very low pressures.

    Personally I think either pump type is acceptable. I would tell anyone to stay a million miles away from a roller pump for CT. I would consider that to be a very unacceptable choice.

    Peter does have a great sprayer and would be a good choice for anyone. For anyone going to NEG he has a beautiful booth with some great things to see and I would suggest no one misses it.
  7. Green Lawn

    Green Lawn LawnSite Member
    Messages: 7

    Thanks for the replies Gentlemen. I really like the model that Peter has, but just isnt in the budget now. The pumps that I have been looking at 12V diaphram pump.Not sure as far as psi goes though.

    I have decided that I will be going with a 1/2" 50 ft hose with prob 35 gallon tank.
    If anybody has anything else, fire away. I love suggestions. Peter I will PM you on Sunday.
  8. OK great Green Lawn, the early AM would work best if possible. My email is below (please use that).

    The main reason I'm not a fan of the 12V on demand pumps is lack of agitation. The larger microbes will settle to the bottom of the tank.

    Turbo, thanks for your kind words.
  9. Green Lawn

    Green Lawn LawnSite Member
    Messages: 7

    Peter, I went ahead and sent you the PM. I knnow you are busy but it will be there when you get time. Thanks Again for your help!!
  10. jonthepain

    jonthepain LawnSite Senior Member
    Male, from Raleigh
    Messages: 595

    Peter, thanks for the photo. That is an awesome setup.

    Greenlawn, we started with a 25 gallon tank and a 12V on demand pump, and outgrew that the first week. Total waste of money.

    Ended up with a Mitsubishi gas pump and a 275 gallon tote attached to our trailer. Also keep a pond fountain pump in the tote while spraying, as an agitator.

    Now I wish I had spent the extra hundred bucks and bought the Honda pump...

    Nothing like Peter's setup, but the best we could do on our budget:


Share This Page