Backwash every half hour or lose flow... HELP!!!

[Earlsfat]

Hi, I'm Jim, sorry to sound so desperate on my first real post... but I'm really at wits end with this pool.

Pool details:

Sylvan, concrete (gunnite?) 40x20 with an 8x5 attached spa that has a spillway between the two. 3' deep at shallow end 8' deep at deep end. 2 skimmers, 2 floor drains in the deep end, 2 floor drains in the spa, one vacuum port, and 2 tiny pool returns. Pump is a Pentair Whisper Flo PN 011514 - Filter is a Pentair FNSP 48 - there's a heater but I haven't used it and have no idea what make or model is. There is also a Hayward cartridge filter on the vacuum line.

I usually have the skimmers set at full and the main bottom drain at about 30% and the spa drain shut off... I have it all returning to the spa. This setup has worked well for 2 years.


The problem:

The pool was fine a week or so ago but overnight turned milky white. Checked the chlorine... none. Shocked the pool, filled the skimmer up with tabs, washed the filter out, added DE... DE blew back into the pool. So I got a new filter thing for inside the housing, the whole entire assembly. Installed it, added about 2 coffee cans of DE, none went back into the pool... everything is operating perfectly but the water is still milky. About a half hour later my wife noticed that no water was coming over the spillway. Opened the filter, clean as a whistle.... put it back together, turned it on, worked fine for about a half hour... then water stopped going over the spillway again.

So I started messing with the valves...and figured I had a bunch of blockages, took the valves apart ran a snake through them, used a hose cleanout bladder... nothing came out, no real issues with the bladder. So I ran the pump overnight with the vale set to recirculate. Ran fine, no flow issues whatsoever ... but pool is still milky (obviously... the filter wasn't involved). So again today I messed with the valves and I can get everything to work for about a half hour... then the flow stops. IF I backwash it twice it runs for another half hour. Doesn't matter if I backwash it for 5 minutes or just a quick on off with the power switch... all I get is a half hour of flow.

I have not added DE back to the filter - I ran it most of last year without DE and it operated fine. I also have a robot that I've been running around the clock just to help move the water a bit... but that's pretty much been useless.

What in the heck do I have going on here? Can anyone point me in the right direction? Would pictures help?

EDIT - The filter pressure gauge used to run about 20-22 PSI... now when I backwash it it drops to about 18... then slowly works its way back up to about 30-32. The higher the PSI the lower the flow over the spillway.

 

[Earlsfat]

So I'm reading some other similar posts... and am gathering that I have an algae problem? Not a pump problem?

I see that I should probably do SLAM... but am also guessing that I need a pool water test kit to understand what all the abbreviations mean?

 

[proavia]

It's most probably not a pump issue. Sounds like the pump is doing it's intended job filtering out the nasties. This issue is chemical - more correctly a lack of sufficient chemicals.

We don't do the typical pool store recommended shock type treatments. Those type products add stuff to the pool that can cause other issues - such as high CYA and CH

How are you testing your water? We don't put much credence in pool store testing and we only recommend 2 different test kits.
Pool School - Test Kits Compared
I prefer the TF100 as it provides the best bang for your buck and contains more of the tests that you will do most often.
TFTestkits.net

Here's a link to Pool School to look over - Pool School - Pool School

As for your selected way to return water to the spa and let it spill over into the pool.... This will reduce proper circulation to the pool as it's doesn't allow returning filtered water to exit the pools return jets. I would suggest you set the spa/pool return to allow a little water to go over the spillway and the majority of water to return to the pool via the pool returns. With a little tweaking, you will still get sufficient circulation in the spa while increasing the circulation in the pool itself.

Also, familiarize yourself with the SLAM process - Pool School - SLAM - Shock Level And Maintain

Okay, I've given you a lot to consider and read over. If you decide to attempt the methods on this site, you will need a proper test kit and to provide us with current reliable test results to help you get started in clearing up your pool.

FC
CC
pH
TA
CH
CYA

We will be here to provide assistance along the way.

Oh yeah - where are my manners..... Welcome to TFP!

 

[pooldv]

Welcome to TFP!

 

[pookiesunshine]

....
I have not added DE back to the filter - I ran it most of last year without DE and it operated fine. ....

EDIT - The filter pressure gauge used to run about 20-22 PSI... now when I backwash it it drops to about 18... then slowly works its way back up to about 30-32. ...

In addition to possible chemical problem, you may also have clogged fingers. Running w/o DE means the fingers were doing the filtering not the DE. When is the last time you took them out to clean them? Or maybe i have your set up wrong. I used to have a DE filter 25 years ago.

 

[Earlsfat]

Gene, I'm just using a bottle of test strips from Leslie's - I've never had to do anything aside from keep the tabs in the skimmers. Going to buy the TF100 today.

FC = off the chart (shocked it last night, added 6 chlorine tabs to each skimmer & shocked it again this morning)
CC - not on strip
pH = 7.2
TA - not on strip
CH - not on strip
CYA = 40-ish
Alk = 80-ish

The pool returns don't seem to blow much water no matter how much water is diverted to them.... over the spillway seem to get the most flow. There really seems to need to be a few more returns in the main pool - or at least something that flows a little better.

Pookie.. the inner filter thing is brand new and has less than 10 hours on it... probably closer to 2 but my memory is embaressing... and when I open the case there is only a light coating of green / white stuff which is the algae I'm assuming. I've sprayed that off twice and the filetr looks as good as it did coming out of the box. I honestly can't believe that running that running it for 10-30 minutes would allow enough water to flow through it to actually clog it up. I even checked to make sure that there wasn't some plastic packaging or something blocking a pipe in side the filter. I did notice that the stupid (I say that because of the ridiculously poor design) little screen on the top of the filter is always crushed in and covered in garbage. Doesn't matter if I add DE or not, and I think that might be one of the issues, but I am not sure.

 

[duraleigh]

a psi of 30-32 indicates a completely clogged filter. Do you have a cartridge filter? DO NOT put DE in a cartridge filter.

 

[pookiesunshine]

Pookie.. the inner filter thing is brand new and has less than 10 hours on it... probably closer to 2 but my memory is embaressing... and when I open the case there is only a light coating of green / white stuff which is the algae I'm assuming. I've sprayed that off twice and the filetr looks as good as it did coming out of the box. I honestly can't believe that running that running it for 10-30 minutes would allow enough water to flow through it to actually clog it up. I even checked to make sure that there wasn't some plastic packaging or something blocking a pipe in side the filter. I did notice that the stupid (I say that because of the ridiculously poor design) little screen on the top of the filter is always crushed in and covered in garbage. Doesn't matter if I add DE or not, and I think that might be one of the issues, but I am not sure.

ok, i misundertood that the filter elements [not fingers, i checked your model info] were same used last year w/no DE. in any case, always use DE, in my opinion, as it was designed to do. YES, the little screen on top being clogged is hopefully your mechanical problem. where is the stuff coming from that is clogging it up?

 

[proavia]

Please fill out your signature as indicated here:
Pool School - Read This BEFORE You Post

This way we can get a better indication of your pool and it's equipment. Use model numbers for the equipment if you can.

You can figure out the pool volume by going to Pool Math and inputting your dimensions and average depth.

 

[Earlsfat]

(Sig updated after last post, sorry)

Filter off of multiport valve (this picture does not show the little screen thing that gets clogged up, but I can't imagine it flows that much water even when it's not clogged, unless I'm not understanding how the darned thing works.

Actually found a picture of the screen tube thing - the stuff clogging it tends to be just little garbage from the pool... bits of leaves, sticks, dirt, sandy looking stuff... occasionally hair (can't convince my wife and kids to shave their heads, lol):

It's in this thing:
]

There's one of these:

But it's on the port that blows into the vacuum line... which I have turned off because it leaks someplace and I use this robot:

The pool return lines really don't blow much at all... which is odd to me.

- - - Updated - - -

Going to look up how to take pump apart to get to impeller and try that tonight.

 

[pookiesunshine]

ok, so you dont think the screen being clogged is enough to cause the massive pressure drop you are experiencing, probably correct. then it must be the fine algae, which is the green stuff. the white stuff must be the DE that blew back into the pool, i'm not familiar with any white algae. does the white stuff resemble de? have you added de back to the filter? got your test kit yet to get some CC numbers to see what's going on? oops. i see you have concrete pool. maybe you are getting some calcium compounds, but need to see some complete test results. Does your robot pick up any of the white stuff (technical term), or is it too fine and pass through the robot's filter? so many questions, no answers. sorry.

 

[Earlsfat]

No worries on the questions - there's a lot of pieces in this puzzle and I understand that to get a decent answer I need to provide useful information.

I don't think the white stuff is DE... the robot is picking it up (slowly but surely) and it's sticky, you have to spray it pretty good to get it out of the filter basket and it does have a faint greenish color to it. It doesn't stink though... at least you would think algae would have an odor to it. There's not huge clumps of it in the basket, but a fine coat on the mesh... I run that robot for about 6 hours straight and the total of that junk is about the size of a table spoon or two... not a whole lot. Of course my kids might be cleaning it out when I'm not looking, they're very antsy to get the pool back open, lol.

No I have not added DE back to filter... right now I have the valve set to recirculate so the filter is out of the equation right now, but when I turn it back to the filter I plan on adding 5 or so coffee cans full of DE to the skimmers. When I left this morning the water clarity as a bit better (those readings I posted above were from around 9 AM), I could actually make out the drains and the plugs at the bottom of the deep end, but the water is still pretty milky. I have about 12 packs of shock left and was going to put 6 in tonight and in the morning and see if that gets it where it needs to be.

I might run to Leslie's tonight and get a full test kit so I can get the results and post back quicker... I need more chlorine tabs anyway.





I really appreciate the interest and help. We might not seem to be getting anywhere but you guys sure have my head back on my shoulders and my confidence is up. Thank you... sincerely.

- - - Updated - - -

BTW... I'll post pictures when I get home... hopefully they'll be useful.

- - - Updated - - -

Quick question... if the flow is decent in re-circulation mode, then I likely don't have any clogs in the pump (impeller) to deal with, correct?

 

[pookiesunshine]

.....

Quick question... if the flow is decent in re-circulation mode, then I likely don't have any clogs in the pump (impeller) to deal with, correct?

i would agree with your assessment.

 

[proavia]

The tube with the screen on it is the internal air bleed. I think it's purpose is to allow any air in the grids and top manifold to escape and move to the top of the tank. From there the air can be manually purged with the external relief valve.

Not that I can find it now, but there have been a few posts here about that screen appearing "crushed". I don't believe it affects the intended use of the internal air bleed though. Gunk getting on the screen should be normal while the filter is on - as the outside of that screen is the input side of the filter (unfiltered water from the pump). The screen prevents debris from flowing into the top manifold and possibly introducing debris into the "clean" side of the grids (after the water is filtered).

I missed you saying that you previously ran the DE filter without DE. That will most certainly plug the grids in short order - hence requiring them to be replaced.

Glad to here you are getting the TF100. Get the Speedstir too if you can swing it. The Speedstir may sound gimmicky - until you use it a few times. I have it and wouldn't be without it. Between the TF100 and Speedstir, I believe you also qualify for free shipping - so the overall cost for the Speedstir is offset by saving shipping costs.

 

[proavia]

My responses in Blue.

No worries on the questions - there's a lot of pieces in this puzzle and I understand that to get a decent answer I need to provide useful information.

I don't think the white stuff is DE... the robot is picking it up (slowly but surely) and it's sticky, you have to spray it pretty good to get it out of the filter basket and it does have a faint greenish color to it. It doesn't stink though... at least you would think algae would have an odor to it. There's not huge clumps of it in the basket, but a fine coat on the mesh... I run that robot for about 6 hours straight and the total of that junk is about the size of a table spoon or two... not a whole lot. Of course my kids might be cleaning it out when I'm not looking, they're very antsy to get the pool back open, lol.

No I have not added DE back to filter... right now I have the valve set to recirculate so the filter is out of the equation right now, but when I turn it back to the filter I plan on adding 5 or so coffee cans full of DE to the skimmers. When I left this morning the water clarity as a bit better (those readings I posted above were from around 9 AM), I could actually make out the drains and the plugs at the bottom of the deep end, but the water is still pretty milky. I have about 12 packs of shock left and was going to put 6 in tonight and in the morning and see if that gets it where it needs to be.
I'd recommend not adding any further packs of shock product. They add unneeded CYA or calcium to the water. Plain old liquid bleach or liquid chlorine is the best way to go. But don't add without knowing what and how much to add. Use the Pool Math link I posted above to figure out how much to add, if additions are actually needed.

I might run to Leslie's tonight and get a full test kit so I can get the results and post back quicker... I need more chlorine tabs anyway.
Don't waste your hard earned cash on test kits or products at the pool store. The pool store doesn't usually carry the test kit you really need - they might tell you it's exactly the same, but it's not. The TF100 is the best bang for the buck, and it's not available at a retail store. Order it from TFTestkits. If you order today, they will ship it out tomorrow and you may have it by Saturday - maybe Monday at the latest. We can suggest what to do between now and when your test kit arrives also.

Chlorine tabs add CYA. Continued use leads to a CYA level that makes chlorine management unrealistic at best. We don't recommend the continued use of tablets.

I really appreciate the interest and help. We might not seem to be getting anywhere but you guys sure have my head back on my shoulders and my confidence is up. Thank you... sincerely.
You're very welcome!

- - - Updated - - -

BTW... I'll post pictures when I get home... hopefully they'll be useful.
Yes they will. Equipment pad too please - from several angles.

- - - Updated - - -

Quick question... if the flow is decent in re-circulation mode, then I likely don't have any clogs in the pump (impeller) to deal with, correct?
Correct!

 

[Earlsfat]

Darn... ran and picked up the pool test kit before you posted that. Yeah, $100.... and the instructions are NOT the best... so if these don't make sense it's my fault.

FC = 1 - I THINK. If i did it right - total chlorine was 2 and free chlorine was 1
CC - Don't know what this is
pH = 6.8
BR = 2
TA - Don't know what this is
CH - 400 ppm
CYA = 90 ppm
Alk = Didn't do, had to roll.

So.... where do I get the chemicals if I'm not to use the pool store junk?

Am thinking of adding a salt chlorinator just make things easier...... if it actually makes things easier, lol.

Pictures:

Pool:


Equipment:


Shot of robot at deep end to show you the clarity of the water:


Shot of spa for clarity:


I backwashed, added DE and turned the valve to filter... within 20 minutes it was at 30 PSI with very little flow. I did notice that the pressure changes 5-15 psi depending on how I have the vales set... I'm not sure if that because of the diameter of the inlet / outlet pipes or if that indicates a blockage... but considering the system is a closed loop, I wouldn't think that the pressure would change by more than 1-2 psi.

 

[proavia]

I can say with a high level of certainty that it's not a filtering issue. It's a chemical issue - actually lack of sufficient chlorine for your CYA level. There is a good chance that you have a nascent algae bloom. Your CYA is high at 90 - it should be around 40-50. Only two reliable ways to lower CYA - drain/replace 50% of your pool water or have an RO treatment done.

You will also need to do a SLAM - Shock Level And Maintain - after you address the high CYA.

Please provide the name and model number of the test kit you bought. A pic of the open box might also help. We can then provide a possible course of action.

If total chlorine (TC) was 2 and free chlorine (FC) was 1, your CC was 1.
FC + CC = TC

pH of 6.8 is too low. Should be in the range 7.2-7.8

No need to report BR - You use chlorine not bromine
TA stands for Total Alkalinity
Alk is probably the same as TA

As for chemicals - most can be purchased at grocery store, HD/Lowes, Walmart. Have a look in Pool School for the items we use.

 

[zea3]

DE filters are very good at filtering fine debris, and you have a very cloudy pool. They will fill with debris very quickly in these conditions, so you will need to backwash and recharge the filter whenever you see a 20% rise in pressure. Once the pool is clear you should be able to go much longer periods between backwashes.

Based on the condition of the water and your test results you should complete the slam process on your pool. The cloudiness may be a nascent algae bloom. If the FC drops to 0 your pool could go green in a day or two. If you are unsure if you need to slam, you can do an Overnight Chlorine Loss Test. If you lose more than 1ppm of FC overnight you need to slam the pool.

As for your testing, Total Chlorine is FC + CC, so if your FC is 1 and the TC is 2 that means your CC is 1 as well. FC is the chlorine that sanitizes the water by oxidation, CC (combined chlorine) is the by-product of the oxidation process. It is what causes skin and eye irritation and has a harsh, heavy chlorine smell. When you have more than 1ppm of CC you need to complete the slam process.

BR is bromine. It uses the same test as FC and is an alternative sanitizer. Unless you have added bromine in the past you won't have any in your water, so you don't need to worry about that test.

CYA (also known as stabilizer or conditioner) protects the FC from quickly breaking down in the UV rays of the sun. The ideal range of CYA for a manually chlorinated pool is 30-50ppm and the only way to get rid of excess CYA is to drain and replace some of the water. How much water needs to be replaced depends on how high the CYA is. With a CYA of 90 you would probably need to replace 60% of your water. To prevent CYA from going higher, do not use chlorine stabilized with CYA, such as dichlor and trichlor granules and pucks.

TA is your Total Alkalinity. It helps to keep your pH stable. Alk is the same thing. Some test kits include instructions for testing Adjusted Alkalinity, but that is not a necessary value. Currently your pH needs to come up a little. You can point the return upward to break up the surface of the water. This will aerate the pool and bring up pH. You can also use borax if you need to bring up pH more quickly.

CH is your calcium, it is a little high so you will want to keep pH in the 7.0-7.2 range, and TA around 70-90ppm to prevent calcium scale formation. If you have been using Calcium Hypochlorite granules to "shock" the pool stop using it. It will drive your CH too high.

Start using either liquid chlorine or plain, unscented bleach from the grocery store to add FC to your pool. If will raise the FC without adding CH or CYA. Borax is also available in the laundry aisle as 20 Mule Team Borax.

Use PoolMath to determine how much of any chemical you may need to add.

 

[Earlsfat]

Yeah... see... I think this is where I'm done. Everything I do makes this worse.... I've already spent $2,000 on pool companies with this POS in the past month to no avail, in fact I think one of them is the reason why i have the issue in the first place. I don't understand the tests, or how to interpret the results to accomplish anything to be able to do it myself... and I appreciate the attempt to help - but draining this thing or RO treatment just spins me into a level of aggravation (end expense) I'm not interested in.

Thanks for the help, but the cover is going back on.

 

[Ocgasman]

Jim,
you have a really nice pool. If you just took some time to read through pool school, it will start to make some sense. Ouch on spending $2k already but think of it as an educational expense. The system taught here works but it does take work to learn and implement this process. Don't give up, swim season is just starting and if you persevere, you will end up with a sparkling clear pool.