How to plumb in a 2 horsepower spa blower?

[Billzer41]

Hello everyone,

I’ve read the forum for years. I’m a DIY type home owner with a 30,000 gallon L shaped salt water pool. It uses a pentair salt generator and pentair 3 horsepower intelliflow pumps. One for the pool/spill over hot tub and one for the waterfall. The waterfall has its own plumbing.

So I had my pool renovated in 2016 and added a spill over spa. It has 8 jets. It’s 96 inches I think. It has two Venturi knobs on top that let you had some bubbles and thrust. The main pool pump runs the spa when the valves are isolated for it.

Anyway... my pool guy who I’ve has for years suggested I add a spa blower. Sounded good. I let him do the install. Except... fail. He brought a 2 horsepower air supply silencer blower. He cut a Tee into the return line/output line to the spa. Wired 240 from the sub panel. I did the breaker and the whip for him. I had it all ready. GFI 15 amp. My part was fine. So he used a standard T and attached it right to the 2 inch return just passed the 3 way valve at the manifold. It didn’t work. When the pump is running water back pressures right up to the check valve for the air supply pump.

I don’t think he knows what to do Now he says it’s not making bubbles because it’s not “strong enough” and maybe a 3-4 horsepower blower will work.... except I don’t even think they make those for residential pools!

His next move is to try to tee into the main return line from the sand filter that goes to the manifold, all the return jets, and the spa. But I am pretty sure the same thing is going to happen.

Where is that blower supposed to be Tee’d into.. the plumbing? Will a “venturi” tee into the return line of the spa do the job? With a Venturi Tee it should just “Inject air” into the line right?

I’m very handy. I’ve changed my own pumps, done my own electrical and plumbing. I knew not to mess with this because I didn’t know enough about it and trusted the pool guy. He’s been in business a long time and I suspect has changed plenty of “bad ones”but I’m guessing he never added one before.

How should this thing be plumbed?

Thanks

 

[mknauss]

The blower needs to be added to the air makeup line for the spa. There should be a line somewhere that air is pulled into the spa when the pump runs. It is part of the Hartford Loop for the spa.

 

[Billzer41]

Hmm.

So the spa is encased in brick and cement and is 18 inches above the pool water line.

It has two Venturi knobs within the spa itself. It’s your typical, white, prefab fiberglass spa. I imagine these Hartford loops you speak of came pre-plumbed with the spa.

There would be no way to access any sort of air lines or Venturi lines within the spa.

The pool guy was literally trying to take the 2 horsepower air pump and T it right into the spa water return line.

He doesn’t understand how this thing works, I’m gathering.

In his defense... my simple brain assumed that would work too... until he did it and I saw that it didn’t.

If he used a 2 inch pvc tee that had a Venturi too and added air via the spa blower would that work or is this thing a done deal and a no go unless I can access an air line under the spa?

I really like the pool guy. He’s a good guy. I feel kinda bad. This is going to embarrass him I’m sure.

Really appreciate the help. Guess I have to figure out what to do with the extra 15 amp breaker if this is a no go!

The blower needs to be added to the air makeup line for the spa. There should be a line somewhere that air is pulled into the spa when the pump runs. It is part of the Hartford Loop for the spa.

 

[mas985]

The pool guy was literally trying to take the 2 horsepower air pump and T it right into the spa water return line.

Fire the pool guy immediately. He has no idea what he is doing.

If the venturi lines terminate at the spa wall, a blower will not do you any good. The air lines must go all the way back to the pad where the blower connects.

Why did you want to add a blower anyway? Their main purpose is to clear the air lines of water when the spa plumbing is designed poorly and air line does not clear of water. When the air lines terminate at the spa, that is about as good as it gets in terms of both control and air injection.

 

[Billzer41]

3 horsepower intelliflow supplies the 8 jets in the spa. The Venturi knobs when open provide some air for sure. The pump is powerful. It’ll fire the jets hard enough to almost be uncomfortable sitting against them. Deep tissue for sure.

I was trying to achieve roaring bubbles for the kids. With the Venturi knobs open there are some bubbles but nothing like shaken soda.

The pool guy was trying to straight T it into the water return line which totally didn’t work out.

Would it be ridiculous to tell him to try a Venturi Tee into the spa return water return line? Do they make them 2 inch? Would that get the bubbles going you think?

 

[ajw22]

Your pool guy never built a pool and does not understand how spa jets with an air blower are plumbed.

See the Jandy blower manual here --> https://www.jandy.com/-/media/zodiac/global/downloads/h/h0507900.pdf?force=1

It has diagrams that show how the water and air lines are separate and get combined at the Venturi Jet outlet. The blower cannnot push against the water in the pipes and it will not add bubbles to the water in the pipes.

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[mas985]

Just for clarity, the above picture is not how your spa is plumbed. Your air lines terminate at the spa so it would be impossible to add a blower.

Would it be ridiculous to tell him to try a Venturi Tee into the spa return water return line? Do they make them 2 inch? Would that get the bubbles going you think?

That might work but I am surprised you do not get a lot of bubbles in the spa as it is now. The issue could be clogged lines. Can you remove the venturi knobs? You might be able to back flush the lines to remove any blockage. Also, if you remove the jet nozzles (deep inside the spa jet), you can try flushing the lines that way too.

 

[Billzer41]

Don’t get me wrong....

It makes bubbles. Nothing is clogged or anything. It’s also only a couple years old. Pre-fab fiberglass.

I’ve seen what a blower can do... crazy water roaring like the Colorado and splashing out of the tub.... it would be a lot of fun for the kids.... and the pool guy suggested it which is what got me into this mess.

So let’s talk using a large Venturi Tee... if that were placed in the return line to the spa... it’s one 2 inch line that runs from the pump to the spa when isolated with the 3 ways valves.

If there was a large Venturi Tee... it should pump air into the line? Or is this a lost cause?

I want to see if I can find a way out for the pool guy to get me some bubbles and save his humility. He’s a nice guy. Very honest. He messed this one up... he’s been doing it for 37 years and has built pools... not sure why he fooled up this one.

Thoughts?

Just for clarity, the above picture is not how your spa is plumbed. Your air lines terminate at the spa so it would be impossible to add a blower.

That might work but I am surprised you do not get a lot of bubbles in the spa as it is now. The issue could be clogged lines. Can you remove the venturi knobs? You might be able to back flush the lines to remove any blockage. Also, if you remove the jet nozzles (deep inside the spa jet), you can try flushing the lines that way too.

 

[Billzer41]

I think I answered my own question. I don’t think that will work either.

I think this guy just messed up and hacked into my very clean pvc and made a mess.

 

[ajw22]

So let’s talk using a large Venturi Tee... if that were placed in the return line to the spa... it’s one 2 inch line that runs from the pump to the spa when isolated with the 3 ways valves.

The venturi tee needs to go into the spa wall at the outlet into the spa. The water and air need to be released into the spa immediately after the tee.