New pump/switch to salt?

[gregh2000]

Hi Everyone,

I am new to owning a pool and we just bought a house that has a 18,000 gal in ground pool that is chlorine right now. I am thinking to replace the pool pump with a variable speed pump because the pump has a slight leak but a new o-ring kit I have read about might fix it. I need to figure out the filter situation as well because it is showing 26 psi which seems very high. It is a Hayward something most of the labels have faded so I don't know the exact model number. I have a Pentair 400HD heater on the pool as well and there is a Polaris pump that is disconnected but they have a Dolphin Premier instead. The pool has a water feature and spa that both dump into the pool. There is one light in the pool that seems to be halogen in an enclosure.

I assume I am going to need a new filter or maybe cartridges, I will see what is inside when I open it up. But right now I am wondering about converting to salt water?

I have been researching and learning for weeks all about the chemistry of the pool before we closed on the house and got this Taylor full test kit. Everything seems to be in the range but there is a decent amount of staining on the pool and could be because the previous owners didn't run the robot enough? I am still learning on that part but if I were to convert this to salt water what else do I need to keep in mind?

I looked the heater can work with salt water, the pump I have now shouldn't care and if I get a new pump then even better.

Here are my questions:

With a new variable speed pump it runs all the time, but then changes speeds. What impact will that have on water feature?
Is there a way to run the water feature and/or spa off a different smaller pump or automate the valves to send the power to that when the pump is on low?
What is the most cost effective way to run the pump without running up the power bill and losing the savings of having the variable speed pump if you have to do 2 pumps?
Also where would you suck the water from for this second pump?

 

[HermanTX]

Welcome to TFP.
If you wish to convert to salt water pool, then you would remove that puck chlorinator and put in a saltwater chlorine generator (SWCG). It appears you have enough room there.

That second pump is a booster pump and they took it out of service. It was to run a pressure side cleaner. So they just looped the suction side of the pump to the return side. That is very common to do when you take a booster pump out of service.

You need a dedicated suction if you want to isolate your water feature circulation. What type of water feature do you have? Some require the flow to go through the filter because of small opening in the water feature.

If you convert to VS pump, then you would find the lowest speed that still operates your flow switch to turn on the SWCG. Let’s say that is 1500rpm. So your SWCG will always produce chlorine at that speed or higher.

If you want to turn on your water feature, you could divert flow to that and it would not go to your pool returns. However, you can still produce chlorine as it all flows back to your pool. You would need to run your VS pump at a higher speed for your water feature.

It is hard to see the pipes leading to the suction side of the pump. Do you have 1 skimmer or 2? Do you have a main drain? Let’s say you had 2 skimmers and a main drain. Then you could possibly replumb to have a second pump use the main drain and flow to the water feature. We need more pictures of your plumbing and more details of your water feature to give more accurate suggestions.

Also show how your current pump is electrically connected. Does it go to a clock type timer or is it an automation system?

 

[gregh2000]

Thank you HermanTX that helps a lot. So there is a waterfall that I have to figure out how it gets its water, it has the pipe that leaves the pump area and goes underground. I think it needs to be filtered before it goes to the waterfall but I need to see how the water comes out. If it is just like a 2" pipe dumping out the top then it wouldn't need to be filtered right?

The pool has 2 skimmers and 2 main drains, then the spa has 2 drains in it too. I have to replace the drains in the pool with the safety drain covers and I am trying to learn how the pipes all work. The controller is a time clock thing and it gets really hot, not sure if it is from the sun or the power. I am thinking to replace it when doing the pump.

Here is a picture of the pool, the robot is over the drain area right now in the picture. There are 2 drains a couple feet apart there in the middle. Then one skimmer on each end of the pool.

Do I need to be concerned about the metal the light is made of before doing a salt conversion?

Does the salt water chlorine cell need to be in the shade? I have seen others on here put up shade. Our pool control area is not 100% in the shade but partial shade and partial direct sun during the day.

Also I was starting to wonder if I could get a variable speed pump for the pool, then use the old booster suction to feed a smaller water feature pump? Since it would be running on low most of the time when the water feature would run it could suck from there I would think? I guess I would have to do math to make sure it doesn't take all the water and the pool still circulates correctly...

If it doesn't need filtered water then I could use one of the skimmers as the suck for a water feature pump and it could be its own loop right? Needing filtered water to the water feature then I would need to do something different I assume?

 

[HermanTX]

My guess is that waterfall just has a 2 inch pipe leading to the top and it flows down. It most likely does not need to be filtered other than with a strainer in the pump. The booster pump is designed for high pressure (to run a cleaner), you want more of a pump for high volume.

You have not stated why you want your waterfall on a separate pump. Is it not flowing properly? It is still circulating water when in WF mode so just trying to understand the need.

The 2 main drains is actually 1 drain pipe but it has 2 suction ports in the pool to be safety compliant. Same with the spa drain. the 2 drain covers are connected to a single pipe.

The SWCG does not need to be in the shade. Although, in this heat, I have put a shade over my whole equipment pad. It is is not a pad idea if you can manage that.

Your light fixture will be fine with a saltwater pool.

 

[gregh2000]

The only reason for separating it would be if I get a variable speed pump I assume it is going to run at a lower rate than the current single speed pump. So when it is running there isn't going to be much flow going through the waterfall with the variable speed pump. Was thinking that if it was separate it could maintain the current flow rates but still get better energy use with a variable speed pump? Or would I be totally losing all of that running 2 pumps?

Yeah that is a good thought to put the equipment in some more shade to take the heat away from it. I am going to try to do that.

I guess I could try to do a variable speed pump and salt water and see what the waterfall does. I just am guessing that since cutting the water flow with a variable speed pump it is going to cut the waterfall flow. That was the whole reason to make it separate to keep the flow rate up for the spa and waterfall while taking advantage of variable speed for the overall energy savings.

 

[HermanTX]

Running a single speed pump and a VS pump at the same time is false economics compared to running a VS pump at different speeds.

Also, do you plan to run your waterfall all the time? If so, you will constantly be aerating the water which will drive up pH and then have the need to add acid to lower pH.

A VS pump is very efficient on energy usage at low rpm but also at mid level rpm. Since your waterfall goes back to the pool I would consider something like this for use of VS pump. This is example only
Let’s say you run your VS pump 24 hrs (which is what a lot of us do, especially with a SWCG). Running at 1500rpm for 20 hrs ,Then for 4 hrs you increase speed to 2500rpm for the waterfall. Based on my VS pump, it would consume less than 7000 watts. A single speed pump consumes 2400 watts per hr - so just 4 hrs exceeds the whole day use of the VS pump.

Also, with the 20 hr + 4 hrs in my example, the SWCG would be producing chlorine all day.

 

[gregh2000]

Yeah running the waterfall would change the chemistry with aerating the water then have to keep an eye on that too. So lets say I did the VS pump and just toss it in where the single speed is I am going to guess it might not have enough power at the lower speed to push the water up the waterfall right? But it would still have enough to circulate the pool and drive the salt cell? Then for a few hours I could have it rev up and run the water feature which also would run the spa and overflow/waterfall that comes out of that?

Or would I need to get automated valves to turn things on and off when the pump turns the speed up and down?

 

[HermanTX]

Or would I need to get automated valves to turn things on and off when the pump turns the speed up and down?

Yes. You would automate a valve that at a certain time it would rotate and the pump would increase speed. Or you can do it manually.

 

[gregh2000]

Gotcha that makes sense. Next up is to learn how to automate valves and then tie that into a VS pump. Thank you for your help!!

 

[HermanTX]

Please consider adding the description of your setup to your Signature, which will aid the experts to quickly tailor responses to your pool and equipment, and you won't need to repeat it in future posts.

This will tell if you have an automation systems and type, and any other questions you may have.
There is a forum for automation if you need to discuss a new subject.