Filter Pressure Issue - Stumped after 4 weeks

[Holz]

Hi,

These blogs are awesome by the way. I have been a silent reader for quite a few months now. We have an IG FG 18,000 gallon pool. Brand new equipment:

Pentair Whisperflow 1 hp 2 speed pump
Triton 60 Sand Filter
2 return lines
2 main drains
one skimmer

Initially when the pool guy set up our system, it was working beautifully for 15 minutes. Then a huge sand dump into the pool. Manufacturers defect on the Sand Filter, and we now have a new one.

Since the replacement, whenever we turn on the pool, open the valves, our pressure is at 17-18. When I add the vacuum, the pressure drops down to 10, sometimes 5. The pressure is not enough to vacuum. There is no air in the return lines. When I backwash the pressure goes back up (I know, backwards). I then start the process again hoping a simple fix will come to me. Our pool guy checked for leaks in the above ground pipes, debris in the pump, nothing. He is stumped. He said it wouldn't hurt his feelings if I hit the blogs. Here I am.

There is only 250 lbs. of sand in the filter. The idea was to vacuum the sand from the pool and catch it in the filter. This isn't happening because the vacuum is not working. Not sure if this affects the pressure. Any ideas would be appreciated!

Thanks,

Holliann

 

[Bama Rambler]

Welcome to TFP.

How does the vacuum hook up?
What type or model vacuum is it?
Is there air in the pump basket at any time?

 

[Richard320]

My pressure drops when I have the vacuum hooked up because the hose doesn't flow as much water as the open plumbing. So I would consider the drop from 18 to 10 to be normal and expected. My suction, however, is super strong.

At the risk of insulting you by asking the obvious....you are filling the hose with water before hooking it up, right?

Is the hose cheap and flimsy and collapsing under suction?

 

[duraleigh]

When you hook up the vacuum, you are restricting the flow to the pump. Your psi is dropping because the suction side of your system (with the vacuum hooked up) cannot give the pump what it wants....it's restricted.

The most common cause is a blockage either in the vacuum hose or at one of the connections.

When you backwash or run without the vacuum, you are supplying the pump the water it wants so the pressure increases.

I almost forgot...Welcome to the forum. :lol:

 

[keene3b07]

How strong is the suction before you plug in the hose. You didnt mention that you had a dedicated line for a vacuum so i am assuming your priming your own hose for vacuuming, correct? That would eliminate the possibility of a clog in the hose. Does the skimmer line tie in with the main drain line? If so its possible suction is being diverted to the main drain.

 

[Holz]

Thank you so much for all of this help. No offense at the obvious...hoping it is something so easy and obvious!

It is a brand new hayward navigator pro. It hooks directly down in the skimmer. The suction feels strong and pulls the connection down in if I connect it with the skimmer on. I do make sure to put water in the vacuum before we try to get it going. There are a few air bubbles in the pump. The pool guy said that was normal to have a few.

The main drain and the skimmer come in together at the valves and move towards the pump, but are on separate lines. The pressure thing makes sense. I don't think I understand why I would have to backwash to bring the pressure back up. I think I am fuzzy on the whole sand filter backwash thing. Anyways, I am wondering if it could be something as simple as a faulty vacuum hose. Would that ever pull the pressure down so far that the vacuum wouldn't work? So strange. Thanks again!

 

[Holz]

One more thought...I read on an Amazon review for our vac that they had too much pressure. They tightened the O ring on the pump and that fixed it. Anyone know what he was talking about, and if that might work?

 

[Isaac-1]

There are several things that could be going on here, can you post a few pictures of your equipment set up so we might spot something that we are not visualizing here.

 

[duraleigh]

Would that ever pull the pressure down so far that the vacuum wouldn't work?

If it has a large enough air leak, it will suck air instead of water and your psi will drop.

A "few" bubbles in your pump basket is somewhat common, but not normal. A system running correctly will have ZERO air bubbles.

Do the visible bubbles in the pump basket increase when you vacuum?

 

[Bama Rambler]

Air in the system will also cause the pressure to go down, so if you're getting air in the pump basket when you hook up the vacuum the pressure will go down and the suction will too.

 

[Holz]

Thanks again for everyone's help. I have attached a picture of the equipment setup. The valve on the left is skimmer. The valve right of it is the main drain. The last two are slide and return lines.

I also have attached a picture of the pump air, hopefully you can see it. It traps these air bubbles at the top. I will have to do some testing to answer the other questions this afternoon. We had snow last night, so I have snow on the cover that should melt this afternoon and I can try a few things with the air and pressure readings.

I am not sure if this additional information is helpful. From speaking to the pool guy, and a guy at the pool store, once we get the vacuum/filter system up and going we can solve the rest of the problems, but just in case....All of the plumbing is new from the valves up. There were not clogs in the lines before we started the plumbing. Our pool was clear when we opened it for the season. No debris, minor dirt settled in the deep end. We have an auto pool cover that seals it off. At this point we put in all the new equipment. From there our pool guy balanced our Chlorine/ph etc. (It wasn't very far off from the winter. We had the vacuum working in the deep end, getting the dirt up when the filter broke and dumped the sand. After the sand dump, the pentair warranty people ran the filter for 24 hours (after this filter you can no longer see the bottom). The warranty guy said to then hook up the vacuum and vacuum the sand. This is when we discovered the vacuum no longer worked. Our pool guy said it was cloudy because the TSD is over 3000. He also said that indicated a filtration problem. He wants to get this figured out, and then work on clearing up the water. I would also mention that the water is still "blue" you just can't see the bottom, and you can see dirt on the steps, assuming this is part of the 100+ pounds of sand sitting at the bottom.

 

[Holz]

Oh, and not to worry, we will be venting the heater, we just haven't made it that far yet!

 

[duraleigh]

If you are still looking for that air leak, check the union on the suction side between the intake valves and the pump. It looks crooked and, if so, it will not seal properly.

 

[Holz]

Thanks Duraleigh. It is definitely crooked. The way the fittings go up and down, it does make it a little crooked. We will have to see if we can somehow fix that. When the pentair people cut out the filter, they put it back together like that.

In answer to the previous question, the visible bubbles in the airbasket did seem to increase. Not exponentially, but some. Also, we get bubbles through the return lines when the vacuum is plugged in, where we get absolutely none when it is not. When my husband pulled the vacuum off the bottom of the pool the bubbles decreased in the basket and went away completely in the return lines when it was floating. At one point the vacuum moved and took off, but stopped shortly after.

My hats are off to you guys! This is the hardest job. It is like fitting a square puzzle piece in a round hole.

 

[Bama Rambler]

That description is a sure sign of a suction side leak that is exacerbated by the increased suction that the vacuum causes. Once you find and fix that leak your vacuum will work properly.

 

[keene3b07]

The filter is not installed properly. That is a triton 2 sand filter i believe. The Top port out of the slide valve is the waste, the middle port is the inlet and the bottom port is the return to the pool. The handle is supposed to be pulled up when in filter mode and down to backwash. This is the cause of your problems.

 

[Holz]

You are amazing! That is it. When I look at the instructions online it is backwards. I am mildly surprised that our pool guy put it on backwards ( he told us he only installs Hayward), but I am shocked that the Pentair warranty guy replaced it and put it on backwards himself. I will post when we get it fixed, but it makes perfect sense. Thank you a million times!

 

[linen]

Nice call keene

 

[Holz]

I just wanted to say thanks again! We had the system re-plumbed, completed a partial drain and refill for high TDS, and we are back in business! Clear water, filter running, vacuum working. I cannot say thank you enough.

 

[Bama Rambler]

Glad you got it worked out!