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Thursday, August 21st 2008, 10:55am

Executive Decisions

Well, as always I'm really overthinking this whole thing. Based on the recommendations above, I've changed my design and any suggestions on the following are appreciated!

1) Water supply will still come from the hose bib - however, I will expect the plastic parts and hose connections to eventually fail since they aren't designed for constant pressure. I'll keep an eye out for leaks and replace this short section of hose and connectors as necessary. Eventually, this will be connected to the main line, but for now I'm going to live with this weak point and design the entire system as if it were connected directly to the main.

2) A short section of hose will connect to a typical-looking section of 1" steel pipe which will come up to hold the PVB backflow preventer 12" higher than the highest valve. I'm unsure if the steel pipe is necessary, suggestions?

3) Downstream of the backflow preventer, on the section of pipe that goes down into the ground, I'll install the 1" 200 mesh Wye filter. This will make servicing the filter very easy as well as making the connections very easy to build. I'm concerned about the type of pipe to be used here and the type of connection to use. I could easily connect the wye filter to the pipe with a permanent connection, but it sounds like the plastic wye filter needs to be brought indoors in the event of a freeze which means it will need a threaded hose-type connection. But threaded connections aren't recommended for constant-pressure use, so now I'm really confused.

Alternatively, I could mount the Wye filter further downstream in a valve box with a permanent connection and just hope I never need to remove it. Being underground will help with protecting it from freezing, but if I ever need to replace it, it will need to be cut out. What a hassle!

4) After the PVB / filter assembly, the piping converts to 3/4" PVC pipe to service 1 zone of impact sprinklers and the 4 drip zones.

As for the valves servicing the drip zones, I'm getting confused over the parts available for putting this all together. Would you mind addressing the following?

1) I want to use 1" valves because they seem to be higher quality. However, all the pressure regulators are 3/4" NPT.

So, it looks like my valve assembly will convert from the 1" valve down to 3/4" at the pressure regulator. Am I crazy for wanting to use 1" valves? It would be much easier to just use 3/4" valves, but the confusing part is why are all the manifolds I can find 1"? I want to use a manifold so the entire assembly will be Buttress connections so it can be easily removed and serviced or have parts changed out as I figure out what I'm doing. But having to figure out all these conversions from pvc to buttress to NPT and from 3/4" to 1" is getting on my nerves.

What's really confusing is that there doesn't seem to be a 1" Male NPT x 3/4" Male NPT adapter available, which is what I would need to get from the 1" valve down to the 3/4" pressure regulator. Arrgh!

2) The valve / pressure regulator will then go to 3/4" PVC to the actual service area where it will come up out of the ground and connect directly to 1/2" poly mainline. Is this cool?

I think that's all my questions, I'm dying to get all the parts purchased and delivered so I can start putting this stuff together and get on with my life! ha, ha

Thanks again!


Supreme Member


Friday, August 22nd 2008, 12:12pm

Pressure Regulators:
What do you mean all the pressure regulators are 3/4"? Right here at the forum's sponsor they sell Rain Bird pressure regulators for 30,40, & 50 psi in both 3/4" and 1" sizes.
HOWEVER, supposedly these are not supposed to be used under constant pressure (and in theory would whould have to be installed AFTER the valve OR install a master valve.
I will admit that I didn't know these were not supposed to be installed before the valve when I installed my system. However, three years later and I havn't had a problem with them being installed "wrong"... but I do only have 70psi at the meter.

For the most part, you can use what ever size valve you want. The only thing that is important is that you make sure the valve is rated for the flow you plan on it using. When it comes to drip irrigation, that means you have to make sure the valve is compatible with a low flow, otherwise it might not reliably turn itself back off. I know Rain Bird makes one that is supposed to go down to 0.2gpm (12gph).

At least for DC and RPZ backflows, it's usually recomended that the filter be installed up stream of the backflow preventer so that the backflow preventer gets the benefit of the filtration to reduce the chances of the backflow becoming fouled.

Master Valve:
A few things have been said about "can't do this under constant pressure". We one solution would be to install a master valve before EVERYTHING. Just about every controller is going to have a master valve hookup. The master valve works such that it comes on when ever ANY zone is turned on. Once you've installed the master valve, then you can put in all those peices that say they are not any good under constant pressure.


Advanced Member

Posts: 88

Location: Seattle Area


Friday, August 22nd 2008, 5:44pm

water quality

Hey, what did you find out about using drip in your hard water? I'm curious.

If you can use drip, stop thinking, and start with a hose end aparatus. That allows you to try it and see how it works. Your emitters or soakers will work on hose end, and can later be directly plumbed to your ingrouond system when you install. The extra parts, a hose end mechanical time, filter and pressure reducer can be had for less than $35.

That gives a chance to build your beds. If you are concerned you may have to dig up an area you planted, put some pipe in, or use a sleeve.

Let me know about drip in hard water, please. Thanks



Supreme Member


Saturday, August 23rd 2008, 11:07pm

RE: water quality

Hey, what did you find out about using drip in your hard water? I'm curious...

Obviously you can use drip irrigation with hard water, it's just a question of how long before things like calcium deposits begin to form.

I have hard water (centeral AL) where over the years we see the calcium buildup on things like shower heads and faucets and shower doors. So far I've been using various drip products (drip emmitters in some places, mini-sprinklers in others, etc) and at least after two to three years of use haven't noticed any calcium buildup that's hurting performant (I've only had to replace one "spinner" out of two dozen so far that was getting stuck, and I couldn't directly link it to calcium problems).

However, the way I laid out my irrigation system was to use underground pvc to get water to the flower beds, then use copper to transition from underground to above ground. I use an elbow and female adapters right at the surface to keep it all low and out of the way. Everything after the copper can be redily replaced when ever needed.


Advanced Member

Posts: 88

Location: Seattle Area


Sunday, August 24th 2008, 2:08am

Thanks, but more info requested

Thanks HookooDooKu:

Yes, I understand everything can be replaced. Why replace it (environment, cost, time etc) when if you plan you can avoid the problems. Austin sits on caliche chalk, its waters high in CaCO3.

When considering any system, planning is the key. Our poster mentioned misters. Does he know how often he will have to replace them. Living in DFW, I replaced my humidity misters in the greenhouse twice a year, and they were brass, with 200 mesh filtration.

Alternatively, if deposits are a true problem in his environment, he can plan his system to avoid such high maintenance items. I mentioned flag emitters, which are easy to diassemble and clean any deposits out. They then are reuseable. Even the Turbo emitters will start malfunctioning after a relatively short time in this water, and even with disassemby and reassembly, many tend to drip at a higher rate (leak). How does netafim CV hold up in calcific waters? I know from personal experience soakers work with some limitations.

I'm trying to make a point. My design information from Puget Sound is not necessarily going to work as well for him, as maybe a neighbor's who has tried drip, and can give him more pertainent insight. I've gardened in many places, including North Carolina, where they have hard water, but not to the same degree as from "The Austin Chalk". He mentioned he has a water softener on his house. Much of the nation has "hard" water, some is harder than others. I fear the poster has some of the worse hard water in the nation. (although I have herd Arizona can be bad too.)

I just want him and others to be sucessful with drip irrigation.

Keep dripp'in :D



Active Member


Sunday, August 24th 2008, 8:57am

Can I mention one more time how appreciative I am of all this advice?

Hard Water
As for hard water, you're absolutely right, Jeff, I've got horribly hard water. Hard enough to foul the little filter on the end of a normal garden hose over a few years. Big chunks of white gunk collects on everything, however; it's really pretty manageable. I looked around on the web for austin drip system users and didn't find anyone complaining online and none of my neighbors use drip (that I'm aware of). I am planning to go to the fabulous Zilker Gardens and the LBJ Wildflower Center for planting advice and other ideas and I'll ask them about hard water and drip systems and report back here because they'll certainly know. I was going to put that off for a few weeks, but I'll try to get out there this week before I finally purchase all these valves and stuff.

My system will be as HooKoo describes their own setup, 3/4" PVC all the way to the beds. I'll resign myself to replacing or fixing emitters. Jeff is concerned about misters so I'll try to avoid them (most people don't advise using them anyway, due to mold or fungus) but if I do have a good use for them I'll connect them in such a way as to be removable so I can just take them off and soak them in a cupful of vinegar for a couple of days. I'll also try to use flag emitters as much as possible since apparently they are maintainable without messing up the poly connection. HooKoo may be familiar with removing shower heads and faucet heads to soak in vinegar, or if one is feeling lazy, just tying a sandwich bag full of vinegar around the shower head, which is what I have to do around here every couple of years so the concern about hard water is certainly valid.

Using Copper from the pvc up to the beds makes sense as it can take a lot of abuse and I think that's what I'll do as well.

Pressure Regulators
Arrgh! I saw those pressure regulators but never clicked on them because they were so much more expensive and from the pressure regulators summary page it wasn't clear that the 30psi PRs came in 1" versions. Thanks!

I will be installing them after the valve, so shouldn't have any issue with valves not having enough pressure, or constant pressure on the PRs. This will also give me flexibility in case I want to use a valve without the PR for whatever reason (additional lawn sprinkler zone or something).

Backflow and Filter
Ok, I'll install the Wye filter upstream of the PVB backflow preventer. Makes perfect sense.

Master Valve
That's another great piece of advice. It's complicated, related to my specific situation, but I don't want the backflow preventer sticking up out of the ground near the garden because the dogs will almost certainly tear it up (2 big golden retrievers) and I've already dug the trenches, and I've got plans for an eventual rainwater collection system that will have pump, blah blah blah. If parts start failing I can correct this, but I'd have to re-dig portions of the system. Not a huge deal, but I'd rather not if I can help it.

I've also resigned myself to making mistakes so when my emitters get clogged or something doesn't work right, I'll just rack it up to ignorance and move on. I'm anxious to get this stuff in the ground and start worrying about the real issues with growing vegetables like disease, pests, planting schedules, canning, frost... I think I've got a pretty good setup now with all this advice, but without experience or paying someone with experience to do it for me I think it's impossible to get this all exactly right. I sure am much more knowledgeable now then I was when I first posted this thread! Besides, there's no fun having some experts come in and do it all for me! I enjoy doing the work myself and learning from experience and when something fails I'll know exactly what to do to fix it without having to call said experts in again...

I'll post what I learn about hard water in the next few days, probably just regurgitated advice from local experts at Zilker Gardens (GREAT garden, if you're ever in Austin be sure to stop by if you're into it. They also have this kick-butt rainwater system) or the LBJ Wildflower Center (again, come visit).

Meanwhile, I'll order these parts and get this stuff installed and probably post some photos so you guys can point out all my mistakes to me after-the-fact. Then, when I finally move out of the suburbs into the country in 5 years or so, I'll be the expert drip system guy and can put in the new system with confidence.



Advanced Member

Posts: 88

Location: Seattle Area


Sunday, August 24th 2008, 12:48pm

Thank You

Sounds great. Don't know why you need a master valve, but can't hurt. I can picture you soaking disassembled emitter parts in vinegar and trying to srub off the deposits with a tooth brush. You would have to get inside the emitters to remove the calcium. Never had much luck with the vinegar methods, but maybe...

You mentioned catchement. Great idea, and totally removes hardness issues. However, has pressure issues. Since you only gain 0.43 PSI per foot of head, you might want to put a second set of PVC in that hard to dig ground when it is open, so you can easily shift form city water to the catchement, but leave both systems in place for dry spells. Other option is a small pump to raise the catchment water to a least 15 PSI after friction losses. It you plan to use gravity, You need to raise catvchment to supply at least 2 PSI at the beds. So with friction loss, the bottom of the tank needs to be at a minimum about 5 feet above you highest emitter. You certainly don't want to loose any more pressure with valves and pressure reducers, so I suggest one filter, and manual full bore ball valves (Like 3/4 inch). They sell nice 1/4 turn brass ball valves (FPT to MHT) at L*wes for $8, or brass ball valve from numerous sources in MPT for about the same price. Full bore 3/4 inch means the opening is 3/4 inch in the ball when you look thru it.

A separate system, because it has special pressure needs and special emitters.

Useing 4 or 8 GPH emitters allows you to run as low as 2 PSI and get 1 GPH delivery. Tape systems (T-Tape, RhoDrip, AquaaTraxx) allow good row coverage, is cheap (although disposable into environment :( ), and operate on as low as 2 PSI.

Or, KISS and use a pump on the existing system. You seem like gadget guy, so may want to play with both ideas.

SO, put a second set of pipes in where you think you might need them. Bigger is always better, and 3/4 inch sch 40 PVC (don't use anything thinner wall if you are going to be digging in the area) @ 4 GPm = 240 GPH loses 1.42 PSI per 100 feet (plus more for fittings). So, not knowing distances, this is significant if yo are working with low PSI top start with. Using 1 inch sch 40 PVC, your loss at the same flow rate goes down to 0.44PSI/ 100 feet. So, even in low volume irrigation, at low pressure, bigger is better.

Finally, instead of using copper, you can use schedule 80 PVC above the ground. The concern is that PVC becomes brittle when exposed to sunlight. Copper does not. Copper, and it's fitings are expensive,asnd shoud be sweated rather than epoxy'ed. Also copper, is a real pressure killer, although in short sections probably not too much an issue. Stil the best for duration, lack of internal rusting, and appearance. PVC becomes brittle, but you can get at least 10 years out of schedule 40 in Texas sun. Longer with sch 80. Look for threaded pieces of Schedule 80 where the sell the risers for irrigaion, they are Grey. The brittleness issue is why PVC electrical conduit is gray colored, BTW, Black PE tubing used in drip has carbon black impregnated to make it MORE UV resistant. Last longest if covered with mulch to shield it from your intense sunlight.

Sounds like you are having fun. Planning is alway a blast (which is one reason I do this). But from experience, ditch digging (especially in Texas Gumbo in the heat) is not so fun. Watch out for fire ants :)

Addenum. Flag emitters are good for gravity systems. So you can use them and maybe get away with one system. Electric valves eat pressure, and you need to make sure they will open at low pressure/flow rates. So, a master valve may not be a good idea. If you plan to use one pipe for everything, consider up sizing to 1 inch. In irrigation, "Bigger Is Better". eMail me for other ideas.


This post has been edited 2 times, last edit by "Lowvolumejeff" (Aug 24th 2008, 1:04pm)


Supreme Member


Sunday, August 24th 2008, 9:59pm

RE: Thank You

...Don't know why you need a master valve, but can't hurt...

The idea behind the master valve was so that only ONE PVC pressure regulator could be used. As I understand, these PVC pressure regulators are supposed to be installed AFTER the control valves so that they are not under constant pressure. So without a master valve, you should be installing one after EACH valve.

Master valves can hurt in that I've heard ( if nothing else its POSSIBLE for a master valve to cause problems with all the valves closing properly (perhaps exascerbating the issue you can have with valves closing under low flow conditions.

Another alternative, however, would be to install a copper/brass pressure regulator before the valves. Little more expensive, but obviously simplifies things.


Active Member


Monday, August 25th 2008, 4:03pm

I'll come back with photos sometime in the next couple of weeks, but wanted to thank you guys again for all your help. Rainwater collection will be a completely different project, at least a year away.

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