New Cartridge filter not cleaning the pool - what could be wrong?

[Mandrake]

Hi,

I just replaced my DE filter with the biggest Cartridge filter on the market (Hayward SwimClear C7030). 725 sq. feet.
My pool guy replaced it on Tuesday morning, and as of today (after about 90 of hours of filtering), the pool is still the same as it was on Tuesday, i.e. a little cloudy. I can see the bottom at the deep end, but it's not crystal clear, and my old filter would clean that easily overnight, even though it was much smaller.

My chemistry is OK. My chlorine was around 5 on Wednesday night, and since it was raining I shocked it, and it was still around 12.5 this Saturday morning, which indicates that I don't have algae problem.

What could possibly have gone wrong with the filter?

Thanks,

M.

 

[mknauss]

Chemistry OK and cloudy water rarely go together.

Can you post a full set of test results?

 

[Jimrahbe]

M,

Dollars to donuts, you have algae... You can easily have an FC of 12 and still have algae..

You do not have a filter problem, you have a chemistry problem..

Please post the following test results...

FC
CC
pH
TA
CH
CYA
Salt.

Thanks,

Jim R.

 

[Mandrake]

Thank you for your replies.
I measured twice today, and got somewhat different results (especially for pH). Here they are (results in the bracket are from earlier today (6 hours ago?))

FC = 12 (12.5)
CC = 0 (NA)
pH = 8+ (7.7)
TA = 50 ( 50)
CH = 120
CYA = 40 (from last week, should not have changed much, its very difficult to measure with Taylor Kit I have)
Salt = 2700 (also from last week)

Typically, my TA is about 60-70, and pH about 7.2-7.4. I found that pH is very stable (and pool clear) even with TA in this range, so I was not striving to get TA = 100, as its very hard to increase TA without increasing pH, so my philosophy is, if it ain't broken, don't fix it.

I found that the most important factors in maintaining clear water is to keep the chlorine around 2-4, pH about 7.3 and keep the filter clean. That's why I thought that maybe something is wrong with the filter. Have no clue why pH went up so much so quickly.

 

[markayash]

I have the Hayward 4030, what does the pressure gauge show?
Unless they put the filter together like they said probably not the filter

 

[Jimrahbe]

Mandrake,

With a CYA of 80, your very minimum FC should be 4 ppm and your target would be 6 ppm... Running 2 to 4 ppm means you most likely have an algae bloom even if you can't see it... I just reread your original post and see where you say your pool is cloudy.. Cloudy is your first indication of algae.

See this chart under saltwater pools.. FC/CYA Levels

To see for sure if you have algae or not you will need to perform an Overnight Chlorine Loss Test or OCLT... Overnight Chlorine Loss Test To do the OCLT you need to get your FC up to 8 or 10 ppm and turn off your SWCG.. Test after dark and before sun up... Any loss indicates an problem..

If you fail the OCLT. which I assume you will do, you will need to do a SLAM... SLAM Process

Filters cannot capture algae faster than it can reproduce, so you need to kill it all using the SLAM procedure.

Either follow the SLAM procedure to the letter or don't do it at all..

Thanks,

Jim R.

 

[Mandrake]

Turned off SWG last night around 22:30, and measured chlorine 8 hours later (6:30 this morning). It's still about the same
FC = 12
CC < 0.5

It's been at this level for about 3 days (with SWG running), and the pool is about the same too. A little visible algae, but not a bloom.
My pool guy showed up last night, and opened the filter which is somewhat dirty, so it seems to be working.
He recommended using PhosFree and Algae Break 90 . Does that work with SWG?
I still think my old DE filter would clear this overnight though (it did in the past), so still suspect something with this Cartridge filter.

Thanks,

M.

 

[Mandrake]

I have the Hayward 4030, what does the pressure gauge show?
Unless they put the filter together like they said probably not the filter

Pressure depends on the water/pump speed, but it is non-linear. I have variable speed pump, and here is the pressure for several speeds (in RPM):
RPM Pressure Power (kwh)
1100 --- 2 --- 150
1200 --- 3 --- 170
1400 --- 4 --- 220
1600 --- 6 --- 312
1800 --- 7 --- 410
2100 --- 10 --- 630
2300 --- 12 --- 810
2500 --- 15 --- 1050
2700 --- 18 --- 1270
3100 --- 24 --- 1866
3450 --- 30 --- 2560

I usually use RPM between 1800 and 2100, which gives me pretty good return, my pool guy suggested 2700, but that seems to high (pressure is more than doubled, and electricity tripled compared to 1800, and the speed is just 50% higher).

 

[markayash]

You can add jacks filter fiber if you want get the really fine stuff out. They suggested adding a whole bag when I had iron but now I just add a 1/4 bag and it seems to help. The whole bag with jacks Magic did get the iron out I cleaned them after a few weeks and they were brown and dirty but the 2nd time looks great.
Silly question but is there any way water is flowing past the filter through a pool cleaner or by-pass? I have had my c4030 for several years and seems to work well.

 

[Mandrake]

Silly question but is there any way water is flowing past the filter through a pool cleaner or by-pass? I have had my c4030 for several years and seems to work well.

This was exactly my thought, but I opened the filter last night, and the grids looked dirty, although there was nothing in between them.
I might have to open it again today to check it.

 

[Mandrake]

Just tested my water in the Pool Store. I haven't been using SWG, so Chlorine went down:

FC = 7.47
CC = 0.25
pH = 7.8
Hardness = 93
Alkalinity = 50
CA = 46
Copper = 0.1
Iron = 0.1
Phosphate = 925ppb
Salt = 2550

Should I use phosphate remover or wait for the filter to do it's job. Th water is blue, but it's a bit milky, definitely not crystal clear?
Since I did not fail OCLT, do I still need to do SLAM?

 

[Mandrake]

Shocked it again last night, and had almost no Chlorine Loss overnight. At 8AM this morning, my chlorine was 16.5, and my CC is under 0.5 (I used step 0.5 in Taylor kit). My pool is blue, and I am pretty sure all the algae is dead, but it's not crystal clear yet, even though ti seems better than yesterday. Is it possible that Cartridge filter is just slow ?!

Here is the paragraph from SLAM Process:

"Depending on what kind of filter you have, it can take the filter a week or more to completely clear up the water, even after all of the algae is dead. DE filters are usually much faster than that, but require frequent attention when cleaning up algae. Sand filters are the slowest, and cartridge filters are somewhere in-between."

Do I just sit and wait, or should I buy a coagulant, clarifier or some other chemical. I hate DE sand (I actually used AquaPerl, but was not too crazy about that either) , but my DE filter would have taken care of this in matter of hours. Is Cartridge filter really so much worse?

Can I use the pool while waiting to become crystal clear?

Thanks a lot!

 

[mknauss]

No need for pool store potions. Those you mentioned can damage your filter media.

It will take time.

You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.

 

[markayash]

Jack's filter fiber makes a cartridge filter more efficient if you want to speed it up

 

[Mandrake]

Jack's filter fiber makes a cartridge filter more efficient if you want to speed it up

Would this have same effect as adding a little AquaPerl (I already have some left for my old DE filter) ?

Thanks,

M.

 

[markayash]

Will leave that question for the experts

 

[sktn77a]

Pool store test results always seem to show a high level of phosphates. Co-incidentally, Phos-Clear is invariably the most expensive water treatment on their shelves(!?)