Hayward Multiport and Sand Filter Issues

TeamBriggs

Member
Jul 11, 2023
11
Western PA
Pool Size
35000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hi! We have a Hayward multiport and Hayward S310S sand filter. We are having multiple problems:

1) The bottom bulkhead is leaking profusely (5 gallons in a couple hours). We have tried to clean and tighten the bottom bulkhead (which is relatively new and does not appear cracked) but it does not seem to want to tighten enough because the inside elbow assembly is notched on top and bottom and when we thread it from the outside, we can only tighten it so much in order to make the notches line up (if that makes any sense).

2) When we put cyanuric acid granules in the skimmer basket without a sock (we have learned to use a sock) they spit back into the pool through the returns in about a minute.
We opened the multiport and do not believe there are any issues with the valve or the spider gasket. We have emptied the sand filter and did not see any tunneling or damaged laterals. We can not figure out how the granules are getting through.

3) The water chemistry is good (according to the local pool store) but the pool is green ☹️

Thanks in advance!

F9AF8C9C-18AB-41A1-A77D-0E000E4E578E.jpeg
 
That fitting requires 2 O rings, one internal and one external. Looks like one inside isn't in place. Not easy to reach in that tank.
Thank you. We’d like to get it apart and take a closer look but yes, getting to it is quite difficult. It seems we’d have to remove the top bulkhead to do so and that one is not leaking so we don’t want to mess with it. Trying to decide to tear this thing apart mid season or deal with the drip until we close it.
 
Any thoughts on why/how the granules are making their way through? If our chemistry is good but the pool is green, it leads me to believe our filter isn’t doing it’s job. We run it 10PM-8AM every night and during the day sometimes.
 
Besides the bulkhead fitting leaks, you have a couple other issues:
1 - Items passing through the filter. You mentioned stabilizer granules being poured into the skimmer and passing through the filter to the returns. Now you probably know that's a "no-no". Never pour granules into the skimmer. Always use the sock method. That said, the granules should've stayed in the sand. The only way I could see granules passing immediately through the filter would be either due to a problem with the MPV or a bad connection within the filter itself. By that I mean a damaged lateral or something else became dislodged inside the filter like a diverter elbow, lower hub assembly, etc. Unlike sand that goes back to the pool from a bad lateral, I would not expect granules to get pulled all the way down through the sand then past a lateral., so I'm more skeptical of the MPV. Do all MPV settings appear to be working properly? Filter, backwash, rinse, waste, etc?

2 - Green water. For that we always start with chemistry. No amount of filtration of water movement will kill algae. Pool store testing is often flawed and their advice not much better. TFP members test their water primarily with a TF-series test kit (see link in my signature) or Taylor K-2006C. We need to see a full set of water test results from one of those kits to help confirm the presence of algae and coach you through a potential SLAM Process to kill and remove algae.

Also see -----> Pool Care Basics
 
Besides the bulkhead fitting leaks, you have a couple other issues:
1 - Items passing through the filter. You mentioned stabilizer granules being poured into the skimmer and passing through the filter to the returns. Now you probably know that's a "no-no". Never pour granules into the skimmer. Always use the sock method. That said, the granules should've stayed in the sand. The only way I could see granules passing immediately through the filter would be either due to a problem with the MPV or a bad connection within the filter itself. By that I mean a damaged lateral or something else became dislodged inside the filter like a diverter elbow, lower hub assembly, etc. Unlike sand that goes back to the pool from a bad lateral, I would not expect granules to get pulled all the way down through the sand then past a lateral., so I'm more skeptical of the MPV. Do all MPV settings appear to be working properly? Filter, backwash, rinse, waste, etc?

2 - Green water. For that we always start with chemistry. No amount of filtration of water movement will kill algae. Pool store testing is often flawed and their advice not much better. TFP members test their water primarily with a TF-series test kit (see link in my signature) or Taylor K-2006C. We need to see a full set of water test results from one of those kits to help confirm the presence of algae and coach you through a potential SLAM Process to kill and remove algae.

Also see -----> Pool Care Basics
Thank you so much. We did learn about the sock method! We took apart the filter and confirmed there are no issues with the laterals. Like you said, we didn't suspect that was the issue seeing as there is no sand in the pool. The MVP was the first place we looked. All appears well with it but clearly something is still not right. Maybe we’ll need to take a closer look.

We actually have the Taylor test kit you mentioned. I will run the tests today and update with results. Unfortunately, we already took the pool store’s advice and put Yellow Klear and Baquacil in last night along with shocking it. Some stuff has fallen out and settled to the bottom this morning but the water is still green and cloudy. We plan to vac to waste this afternoon.
 
I'd guess that the lack of an internal 0-ring on the bottom is allowing things to go directly to the other port, rather than forcing things through the laterals/sand bed.

As Texas Splash noted, your chemistry is likely NOT good. What the pool store says may not at all be what you really need. There's a strong dependency on Cl levels and CYA levels. Your Cl may look "good" to the pool store, but be far below what you really need if your CYA is in a moderate to high range. As he noted, time to get a good test kit, and verify all your levels. Case in point - if you really had enough Cl the water would not be green. Perhaps cloudy, due to the poor filtering, but not green. It's generally bad practice to start dumping in chemicals without knowing where you are starting from....but while you wait for your test kit to arrive, report here all the levels (Cl, CYA, TA, Ph, etc.) the pool store told you, and we can give some conservative "what to do" advice. Once you can test yourself, the advice can become much better.

{Later edit} - the subsequent posts seem to make it a bit more interesting - time for me to bow out, and let the experts advise!
 
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we already took the pool store’s advice and put Yellow Klear and Baquacil
Oh boy. That might complicate things a bit. What was the pool store thinking? :hammer: Let me ask @Donldson to join the conversation.
 
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Besides the bulkhead fitting leaks, you have a couple other issues:
1 - Items passing through the filter. You mentioned stabilizer granules being poured into the skimmer and passing through the filter to the returns. Now you probably know that's a "no-no". Never pour granules into the skimmer. Always use the sock method. That said, the granules should've stayed in the sand. The only way I could see granules passing immediately through the filter would be either due to a problem with the MPV or a bad connection within the filter itself. By that I mean a damaged lateral or something else became dislodged inside the filter like a diverter elbow, lower hub assembly, etc. Unlike sand that goes back to the pool from a bad lateral, I would not expect granules to get pulled all the way down through the sand then past a lateral., so I'm more skeptical of the MPV. Do all MPV settings appear to be working properly? Filter, backwash, rinse, waste, etc?

2 - Green water. For that we always start with chemistry. No amount of filtration of water movement will kill algae. Pool store testing is often flawed and their advice not much better. TFP members test their water primarily with a TF-series test kit (see link in my signature) or Taylor K-2006C. We need to see a full set of water test results from one of those kits to help confirm the presence of algae and coach you through a potential SLAM Process to kill and remove algae.

Also see -----> Pool Care Basics
Okay water test results:
0<FC<1-2
0<TC<1-2
CC = 0
pH = 7.6
TA = 80ppm
CH = 110ppm
CYA < 30ppm (pool store said 22ppm yesterday)
Sat Index = -0.25

That is everything I was able to test with our kit. Is there anything else?

We have always struggled with our cyanuric acid. We add it daily but when the granules were spitting back into the pool I don’t think it was dissolving properly. Now that we use a sock, I’m hopeful it will come up quickly.

Pump shuts off at 8AM. I turned it back on this morning and the pool has already gotten more blue. Still very cloudy. Again, we plan to vac to waste this afternoon. Picture shows a ledge. On the left is 8ft deep and on the right is 12ft. 3412F987-D64A-44A9-A170-3680E8781F8E.jpeg
 

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Ouch. Could you post pictures of the containers of these products? And let us know how much of each you added.
Here’s what we did per pool store:

Monday night:
6 capfuls of Yellow Klear cast into pool
1 bag of shock into skimmer
1 bag of shock mixed in a bucket, cast into pool

Tuesday night:
3 capfuls of Yellow Klear (remainder of bottle)
10 capfuls of Baquacil into skimmer
1 bag of shock into skimmer
2 bags of shock mixed in a bucket, cast into pool
(We were also told to put robot, toys, and floats in pool overnight to kill suspected mustard algae)22BD848A-C7CD-460C-B719-5BB204184F60.jpegC3CDECC5-5583-4E99-80B9-71D49DF3A013.jpeg6EC0B607-980B-4E5D-AB7A-0F148273F540.jpeg209EECBE-3CC3-4080-868B-113FAFB1E41A.jpeg

We add 1/2 cup of cyanuric acid to sock in skimmer each day.
 
In doing other research this morning, we think we are putting too much flow into the multiport. Our pump runs at 3405RPM on high and 2205RPM on low (I know we can probably change this programming but we’re still new at this). When we looked up a chart for the Pentair Intelliflo VSF, 3405RPM generates over the allowable 75GPM that the MPV is rated for. Could this be the cause of the granules issue? Weeks ago, we noticed more granules at the high speed so we started running it on low (2205RPM) before we’d add the granules (before we learned about the sock).

I’m sorry if that seems like an obvious problem (RPM to GPM) that was overlooked. Again, still new at this.
 
Ok, the only good news is that the Baqua is just their brand of floc. This concludes the good news...

Did you switch your filter to recirculate before adding the floc? That stuff can really mess up filters, which is one of several reasons we almost never recommend it here.

The real problem though is that sodium bromide. I have no idea what a cap full is (love these pool store measurements) but if you added the entire two pounds of bromide to the pool then you now have a bromine pool. That's a big problem, CYA does not protect bromine from sunlight so you'll always be fighting massive bromine loss (chlorine and bromine register the same on tests, you cannot tell the difference) until removing virtually all the bromide. There's only one way to do that: completely water exchange.
 
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Ok, the only good news is that the Baqua is just their brand of floc. This concludes the good news...

Did you switch your filter to recirculate before adding the floc? That stuff can really mess up filters, which is one of several reasons we almost never recommend it here.

The real problem though is that sodium bromide. I have no idea what a cap full is (love these pool store measurements) but if you added the entire two pounds of bromide to the pool then you now have a bromine pool. That's a big problem, CYA does not protect bromine from sunlight so you'll always be fighting massive bromine loss (chlorine and bromine register the same on tests, you cannot tell the difference) until removing virtually all the bromide. There's only one way to do that: completely water exchange.
What do you think about this procedure for testing chlorine vs. bromine?8069E75F-EA70-493A-B6FC-67A57BBF57BC.png
 
It would work because free bromine and combined bromine register the same on an FAS-DPD test, while the free chlorine and combined chlorine register separately. You would need an FAS-DPD chlorine test and a source of pure ammonia, not cleaning ammonia. However, the test really isn't needed. If you add salt to water, it becomes saltwater, right? You don't need to test for it to know it is saltwater because you added the salt.

Bromide is a salt. If you added it then you can be assured it is in there creating bromine from chlorine. There's no need to attempt a test when you know it is there.
 
When we put cyanuric acid granules in the skimmer basket without a sock (we have learned to use a sock) they spit back into the pool through the returns in about a minute.
Probably coming through the internal air relief tube.

Normally, the tube should have some sort of a screen.


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It would work because free bromine and combined bromine register the same on an FAS-DPD test, while the free chlorine and combined chlorine register separately. You would need an FAS-DPD chlorine test and a source of pure ammonia, not cleaning ammonia. However, the test really isn't needed. If you add salt to water, it becomes saltwater, right? You don't need to test for it to know it is saltwater because you added the salt.

Bromide is a salt. If you added it then you can be assured it is in there creating bromine from chlorine. There's no need to attempt a test when you know it is there.
I hear you. 😔 I guess I was just praying maybe we didn’t add enough to nuke it. Assuming we now have a bromine pool (and we can’t drain all 35,000 galloons right now)…what now? Aside from burning through tons of chlorine, is there anything else we should know or do?
 
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