# tow Behind sprayer, 21 or 31 gallons



## Belgianbillie (Apr 3, 2018)

I have a 32,500 sq feet lawn. Should i get a 31 gallon tow behind or 21 gallon tow behind.

https://www.northerntool.com/shop/tools/product_200645939_200645939

https://www.northerntool.com/shop/tools/product_200646314_200646314?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Lawn%20%2B%20Garden%20%3E%20Sprayers%20%3E%20Trailer%20Sprayers&utm_campaign=NorthStar&utm_content=282780&gclid=CjwKCAjw0N3nBRBvEiwAHMwvNooYBrN_Z3LTpI8AwZxQazfOBtyXRQkJm9V8B9TmsIx-R_AEpq8UsRoCJMkQAvD_BwE


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## Jgolf67 (Apr 27, 2018)

Just depends on how much water you want to use. I had the 21 gallon northstar for about 3 years and it worked great for my 38,000sf. I had it calibrated to run 20 gallons per acre which is a little low volume but never had an issue. If you want to use more carrier with less fill ups I would say go bigger. Rest assured you will like either one, they are great sprayers.


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## CenlaLowell (Apr 21, 2017)

When or if you do get this machine add your thoughts here.

https://thelawnforum.com/viewtopic.php?f=4&t=8635

I think this is a really good product that I'm interested in purchasing later this year. If we can have all the information in one thread would be great.

I would get the 31 gallon fill it up and call that good. I know it's not 1gal/1k but it's all in how precise you want the application. That would suffice for me.


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## Drewmey (Oct 3, 2018)

Considering it is only an extra $40, I would go with the 31 gallon. I feel like it would be nice to be able to spray almost your whole yard at 1 gallon per M. Which is a fairly common recommendation on the back of products although not really required.


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## ForsheeMS (May 21, 2018)

I bought the 31 gallon. For the small difference in price and if your mower will pull the extra weight there's no good reason to go with the smaller sprayer.


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## HomerGuy (Jun 5, 2017)

I'd for sure get the 31 gallon unit for that size yard.

I strongly considered the 31 and 41 gallon tow behind for my yard. I ended up going with a 26 gallon Northstar ATV sprayer that I mounted to the front of my ZTR with a 4 nozzle spray boom on the back. I was concerned that the 31 gallon may not have enough GPM for proper agitation (see my thread here: https://thelawnforum.com/viewtopic.php?t=7802) and the ATV sprayer has a 5.5 GPM pump compared to the 2.2 GPM pump on the trailer.

Jury is still out if I made the right decision. The mounted sprayer scores major bonus points for maneuverability, but also takes some time to put on and take off the mower, whereas a trailer sprayer would be faster to connect.


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## FlowRider (Apr 7, 2019)

I actually looked at both of these very closely when making my own buying decision.

On sale, the price difference between units can be as low as $20.

I wanted to be able to spray mixtures of fertilizers, pre-emergents such as Prodiamine, and post-emergents such as 2,4 D and Quinclorac, among others, plus plant growth regulators. Having spare tank capacity allows for customizing your spray applications by blending what you mix without bumping into tank capacity limits.

Here is an example. 2.5 gallons of 20-0-0 fertilizer mixed with 12.5 gallons of water takes 15 gallons of capacity for 15,000 square feet. Doubling up on that gives you 30 gallons of tank mix. Adding one gallon to the 30 gallons allows you to spray 2,4D with fertilizer, so if you blanket spray a large area, you can kill weeds while you feed your grass all at the same time, and not have to stop to refill your tank.

So I went with more capacity. I don't need it all the time but it is there when I do. And if you get a bigger place someday, you're all set....

It has been awhile since I compared them side by side in the store but if I recall correctly, I think the frame on the 31 gallon looked more sturdy than the 21 gallon (added weight makes this recollection stand to reason) and I wanted the beefier frame, so IIRC, that was a factor too.


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