Swapping out MP-Rotator Sprinkler heads
 

It’s been suggested that I swap out my MP Rotator sprinkler heads for traditional popup spray heads. Any observations other than the flow rate difference?

MP rotators are not nearly as influenced by the wind.

IMHO, you may want to involve a qualified irrigation specialist before you make these changes, not sure why you want to change out the rotators, we have been using these since 2013, and outside of an occasional replacement, they work great.

If you irrigate with pond scum water, MP rotators plug up often. The wider flow path through the fan spray heads allows more of the scum to pass through and thus less cleaning or replacement needed.

The super for the developer did a poor job of verifying that the irrigation sub had properly spaced the sprinklers and contemplated overlap and overall coverage. Not having had sprinklers before it took me a while to catch onto this, too late to address it before my year was out. Wanting to balance the system out without myself or a contractor having to dig up the lawn and splice new pipe in, I embarked upon a merry journey of selective replacement of rotator heads with sprays.

The sprays put out alot more water than the rotators, which is what I was looking for to more thoroughly drench some spots. Unfortunately, every spray one puts in a zone reduces the height that the other sprinklers will raise up out of the ground, and it reduces the water the rotators will put out.

Changing all the heads in a zone from rotators to sprays will not solve the problem either, as they will all put out feeble spray, leaving arid zones.

So it has finally ended up that I have a very few sprays in strategic locations, where the compromise of the rotators not rising up enough is worth it.

Being able to turn up the pressure or water volume in zones would be very handy, as all heads, both rotators and sprays, can be individually adjusted for fan arc etc, but I saw no way to do this on my system. The zone devices in the box with the purple lid are not adjustable, and whether they are or aren't, it seemed like some sort of pump in the line before them would be a good idea.

So no do not replace all your rotators with sprays.

Unrelated to this, everyone should get a main filter on their irrigation. As mentioned in threads here before, cleaning thirty individual heads is miserable work, and when we are in drought as we are now, the water being sent is full of muck, so that arduous cleaning job would have to be done again very soon. Much simpler just to flush or brush one big one.

The MPs need more overlap, but they also cover a LOT more area. You would most likely still need different spacing.

IMPORTANT, MPs use very low volume so pressure on the same number heads will vary greatly as well if sprays.

I would suggest going to Standard rotors and fewer heads. You can get the coverage and increased volume.

How ever you tune this, with different heads, you will need a change in spacings and typically number of heads on each zone.

I had my orientation on the sprinkler system just a week or so ago. Our home is in Well Point. The builder lays Saint Augustine sod exclusively. I saw somewhere that we should mow Saint Augustine at around 4”. The rotators installed are 4” housings, which, I assume, pop up a distance of less than 4”. This means that the grass blades will obstruct the water streams resulting in less coverage. Hunter does produce a 6” rotator, but installing these was not an option.

3.5" is fine on St Augustine Floritam. 4" would be more for Bitter Blue, and that isn't used.

@Itcdfancher

My 2019 build home had almost all sprayer heads by the time we moved in. I had one zone left in the back with the rotators. Looking at the specs on Hunter their rotator nozzles have discharge angles between about 15 and 20° depending on how far the nozzle is designed to throw water. The fixed nozzles, discharge angles very depending on the radius the nozzle is designed for. However, the lower distance nozzles, 2, 4 and 6 feet discharge at 0°, with the eight and 10 foot nozzles at 15°. Larger point being, even with your 4 inch pop-up if you keep the grass trimmed well around the nozzles I think the pop-up height plus the delivery angle of the rotators should do OK for you. I have had to raise pop up bodies and/or go to the 6” heights to get my shorter throw fixed nozzles high enough.

I'd go with the one that gets less hit by the lawnmowers! There are many times they don't retract all the way after they sprinkle. Not sure which one is best but it will happen.

Before changing to a spray head watch this https://www.youtube.com/watch?v=iCJtmcH0j-w If an area is not getting enough water lengthen the run time. Zoysia grass typically needs about 1 inch of water per week. St. Augustine generally requires more water than zoysia—about 1 to 1.5 inches per week. Use a rain gauge or tuna cans (cat food cans) to measure how much water your sprinklers are delivering to an area.
The Hunter MP heads and the Hunter spray heads both have a filter in each head, They should be cleaned at least once a year. Just pull the pop-up part up, clamp it, twist the head off and find the filter rinse it and replace. You tube has videos on the process. I installed a system filter as someone else suggested. You tube also has videos on this.

If you are thinking of going from the 4" heads to the 6" there is a potential problem. The body of the 6" pop-up head is about 8 1/2' long that is 3' longer than the body of the 4" pop-up head. So if you want to raise the body an inch look for a different way.

That "once a year" time only applies if your irrigation water is from potable water.
If yours is from pod scum water, they need to be cleaned weekly now because there are so much debris, sediment, bugs, and organics being delivered during this drought. It's as if there are no filters at all on the developer's pumps.
Or put in a prefilter and clean that weekly.

Yes, I have experienced this very thing here in Dabney. I started out with some 1 1/2" extender tubes that connect between the top of the sprinkler tube and the head, but those create another fine thread joint that could leak or fail over time. They are called KAP-ITs and can be purchased from Wal-Mart in a 10 pack for around $35 (link below). The better solution is to raise the sprinkler heads up about 2" or as high as you can without them getting dinged by a mower blade. You will have to dig down about 10-12" with a trenching shovel and when you reach where the flexible hose is, pull the entire head up gently about 2" and push some sand underneath that gap, pack tightly, and refill the hole. You will likely need some additional sand to completely fill the hole you dug out and to get the head exactly where you want it, so it is helpful to have a bad of sand handy before you start. Not a bad job, takes about 10 minutes per head once you do a couple of them. If you are not using donuts, you might consider those as well. They are not great since the St. Augustine quickly grows around the donut and inside it, but if you clean and cut the turf around them a few times a year, you can at least see the sprinkler heads and make sure they can pop up freely without the wiry grass vines stopping them. Still not sure why they didn't go with Zoysia grass down south, but I am sure cost was a big factor.

Robot or human?