Slic-tite and wet environment question

I have a three valve irrigation setup I'm re-doing.
I have the cemented connections done to the pipe from down under.
Under pressure so far for almost 5 hours, so I think I'm good there.

http://www.gthomson.us/projects/landscaping/sprinklers/fifthandlast.jpg

Just above the sched 80 reducer is teflon tape, nipple and cap.
It is leaking there a bit, but I expected that - didn't tighten fully.

Where that teflon tape connection is, I want to get that right on the 2nd attempt, rather than the 5th, this time.

It sounds like teflon tape is for metal for lubricating it, not sealing of PVC.
Okay, so if that's true, who wants to tell the big box stores that?

So instead of that teflon tape, I'm looking to use Slic-tite on those nipple threads, and then on all the threaded connections after that for the 3 valve setup.

With the water off at the street, once I take out that nipple, there will be a steady, but slow/low pressure stream of water coming out of that pipe for at least a couple days. (Is that because of higher ground lines slowly going to lower?)

With the slic-tite sealant, if I'm understanding right...
That slow water stream isn't a problem, it's actually what it's best at dealing with(?). So with Slic-tite on the threads as I screw in each new piece, it will seal it good as I go along, right?

Is there any reason, that you can think of, that will cause a problem with threaded PVC links that are wet when using Slic-tite? The key words there for me being 'that are wet'.

Check the label. In my mind the Slic-tite product is oil based so not appropriate for plastic. I always use Teflon tape on Plastic threads with perfect results. Every fire sprinkler contractor I’ve ever seen, uses teflon plus Slic-tight. For good measure many plumbers use a bit of plastic-compatible joint compound.
As is often repeated: PVC breaks down overtime and becomes embrittled and readily cracks with soil expansion and contraction.
Since you seem to not have a lot of experience I would recommend a union if you’re going to rely on threaded joints and don’t have confidence.

Teflon tape rector seal or Teflon paste that's what I use

Rectorseal...my go to stuff.

Okay breplum, you're now messing with my mind on that last post, right? I'm new to all this, and very inexperienced at it, but a union in this case, there, makes no sense to me.
Please tell me you're just effing with me, or if not, why does it make sense?

The rectorseal tape is looking like the way to go for me on this one.

The union allows you to unscrew and tighten the fittings as needed,
I always used Teflon tape with slictite over it then tighten without over torgue
never had a leak

Thank you all for the responses.
And sorry breplum if my reply seemed disrespectful, it wasn't meant to but, but looking back I think it might have. I thought using unions underground was taboo - just don't do it. I'm not sure why I think that. But that's why I thought you were just messing with me.

Tried some Proselect 1" x 10mil tape on this go around - that was a mistake - leaked like crazy. I thought it was like Rectorseal tape. I guess not, or at least not useful for 1" fittings. That tape must be for larger pipe diameters it seems like.

Re-did again today with Rectorseal paste - I'm a believer now in Rectorseal paste. I think Slick-tite is probably very similar, and other brands probably work well as well - as long as the person using them knows when/where/why they work best.

Got my sprinkler valve setup to the next step, and water has been on for at least a couple hours, so these fittings are under pressure for a couple hours - no leaks.
And I do plan to use a union on the outgo side of the valve after it's on. That way I can shut off the water, undo the union, and deal with problems without having to go underground for quite a while - I hope.

So far, I think this is my best work yet - a bit messy on the rectorseal, but functionally the best so far.

http://www.gthomson.us/projects/landscaping/sprinklers/valvefix2.jpg

Lately i have been using Blue Monster pipe dope and Teflon, has been working well.