Cloudy water - maybe algae?

[kingkev]

Have been doing your method since last year, got myself that nice $100 test kit from taylor too.


Levels at the moment are

FC 15
TA 140
CYA 35
PH 7.4

Ive been running the filter (sand) nonstop with the chlorine level this high for about a week now and its still cloudy with a tint of green. I try vacuuming (not to waste) but it only gets the stuff off the floor and then kicks up the rest to make it more cloudy.

I did use pucks in the beginning of the season to help raise the CYA (I know I shouldn't have).

Also im not sure if this is relevant but the top part of the filter, the female housing for the plastic little screw, has cracked and now constantly lets air out. I sealed I with duct tape to keep the pressure up (which it stays at 15-20 no problem) but I do hear hissing.

Not sure what to do except keep bleaching and filtering.

Also how often should I be backwashing? The pressure doesn't build up beyond 20 to give me a red flag to backwash, although every time I do it is very thick green.

Thanks!

 

[Texas Splash]

For TFP standardization's sake, let's round-up that CYA to 40 and call your SLAM FC level a "16" based on the Chlorine/CYA Chart. You're right in that area. Is there any chance your CYA could be higher than what you believe? That would require a higher FC and perhaps explain the lengthy SLAM process:

Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.

In addition, have you been scrubbing the pool each day to break-up any biofilms on the surfaces of the pool? Have you removed/inspected any applicable ladders, steps, or lights (behind them)?

The air leak you refer to would interfere with a proper psi reading to let you know if the filter was getting dirty. You would want to backwash when the filter increases by 25% from the clean pressure. In addition, a leak at your filter might allow water to flow in the opposite direction should you ever shut the system down, thus losing prime, so you'll want to repair that air leak when you get a chance. But for the SLAM, continue to maintain that FC of 16 and ensure you're meeting all the other requirements on the SLAM page. If you have any questions, please let us know.

 

[kingkev]

Yea the cya reading was on the safe side, I'm still able to see the dot at 30 so I figured I'd round up a bit and add more chlorine.

I've been scrubbing every other day as the gunk takes that long to accumulate. Should I try vacuuming to waste instead? Is it possible it's too fine for a sand filter?

 

[Texas Splash]

You certainly can vacuum to waste if you suspect there's a lot of junk down there. Also, if you haven't done so in a while, you might consider a good ssand deep clean as noted on the Deep Cleaning a Sand Filter page.

 

[kingkev]

When I vacuum now, it sometimes looks like the returns are coming out slightly green, although it could just be because the water in the pool has a green tint to it at the moment. Can sand filter out algae without throwing a lot back in to the pool?

 

[max2k]

Have been doing your method since last year, got myself that nice $100 test kit from taylor too.


Levels at the moment are

FC 15
TA 140
CYA 35
PH 7.4

Ive been running the filter (sand) nonstop with the chlorine level this high for about a week now and its still cloudy with a tint of green. I try vacuuming (not to waste) but it only gets the stuff off the floor and then kicks up the rest to make it more cloudy.

I did use pucks in the beginning of the season to help raise the CYA (I know I shouldn't have).

Also im not sure if this is relevant but the top part of the filter, the female housing for the plastic little screw, has cracked and now constantly lets air out. I sealed I with duct tape to keep the pressure up (which it stays at 15-20 no problem) but I do hear hissing.

Not sure what to do except keep bleaching and filtering.

Also how often should I be backwashing? The pressure doesn't build up beyond 20 to give me a red flag to backwash, although every time I do it is very thick green.

Thanks!

filter and the rest of the system are normally filled with water so instead of hissing you should have a little fountain. If that is not happening you should fix your filter first IMO. I also don't understand how duct tape can hold any pressure, most likely you got none or it's not just duct tape alone. Your FC is at SLAM level for your CYA, hope this was intentional and not test error.

 

[kingkev]

I replaced the dome lid and now my filter runs at a constant 20 after a backwash and rinse cycle.

I have been adding DE to the filter and after a few hours it spikes to 25 give or take. I've repeated the process a few times already with the same results.

The water still seems to be cloudy and slightly green.

Am I on the right path by just keeping the FC high and vacuuming when I can?

And is it good that the filter pressure goes up when I add the filter aid in?

 

[Texas Splash]

DE filters are notorious for great filtration, but that also means they fill-up quick with algae. You'll have to watch it closely during the SLAM. Yes, maintain that FC of 16 based on your CYA of 40. That's #1. Review the SLAM page each day as a memory jogger so you don't forget the things you should be doing. But maintain 16 as much as you can consistently. Eventually the bleach will get the upper hand.

 

[max2k]

... filter pressure goes up when I add the filter aid in?

what is 'filter aid'? I hope it's just DE media otherwise I'd ask to just stick with liquid bleach until the water clears out. I know for sure no algae can survive SLAM chlorine level for more than few days provided SLAM level was maintained, tests were accurate, filter/pump were doing their job and no extra unknowns were introduced to the mix. You might end up with a lot of dead algae you need to clean/vacuum but that's life. At the end nothing will be eating your chlorine so if the pump/filter working you get sparkling pool after some brushing. Anything else and you're on your own as you might not find too many ppl around here familiar with the effect of the last thing you added.