Circulation Question

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#1
Greetings all, this is my 1st new thread here at TFP!

I was recently tasked with helping the In-Laws with their pool. Having never owned a pool, but being very interested in the chemistry side of things, I stumbled across TFP by accident, and man, what a GREAT mistake that was!

Brief summary of what I was dealing with. There was a MAJOR algae problem, water was green and cloudy, couldn't see more than 6" into the water before my hand disappeared. Using BBB and the calculator all the algae is dead, but the water is still INCREDIBLY cloudy, white now, not green. The way I figure it, this is just the dead algae floating about and it needs to be extracted via the filter. I have been cleaning out the filter cartridge once or twice a day. It now has a grey sludge building up in it, before shocking the pool it was green.

The pool is a 24' Intex above ground pool with a vinyl liner and cartridge filter. I shocked the pool Friday night, it is now Monday, and the pump has been running 24/7. I have seen no significant improvement in the clarity of the water since shocking. There has been a slight improvement, but I am not sure how much of that is my mind playing tricks on me. My question is this, with the surface skimmer being the only inlet for the pump, am I getting any decent circulation? I currently have the return pointed to create a flow, I can see any debris on the surface going round and round the pool, but is there anything I can do to ensure that I am maximizing the filters effectiveness?

Also, the pH is currently low, about 6.5, I have done nothing to correct it yet. I know I need to, but with regards to the cloudy water, could this be contributing as well?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
You definitely want to raise the PH to at least 7.0 right away. PH below 7.0 can damage the pool surface. It would also be a good idea to post a complete set of water test results.

It can take the filter up to a week to clear the pool, running 24/7. However, you should see a visible improvement each day. The fact that the filter is catching stuff does indicate that the filter is working. The stuff you are catching in the filter has changed color because the algae is now dead and has been bleached out by the chlorine.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,206
East Texas
#3
The biggest hing you can do to keep circulation up is to keep that filter clean. A couple of extras on hand to swap out with while cleaning the dirty one would help if you're short on time. It could take a week to clear with that much dead algae while staying on top of the cartridge cleaning procedure. Fix the PH. We love to see a good set of test results too.
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#4
Wow, that was fast. The level of activity on this forum is really astounding. I didn't post results because the only full results I have are from a local pool store pre-shock. I shocked based off of those readings and the calculator. I then just kind of did my best guess work with regards to adding more chlorine while shocking. I ordered a test kit on Friday, but it hasn't shown up yet and I was too impatient to wait on it before shocking.

I feel like I have a pretty good handle on the chemistry, just didn't know if there was anything to do to ensure that my filter is working at max capacity since the only inlet is the surface skimmer, and I only have one return.

Are there any best practices for "aiming" the return on a round above ground pool like this?
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#6
Full test results!

So, my TF-50 came in today, and like a kid with a present I couldn't wait to use it! So I tested twice today.

Lunch(noon):
FC - 18ppm
CC - 0ppm
TA - 0ppm
CYA - 75
P.H. - Low (looked to be below 6.8, which is as low as my kit will go)

I know that with FC that high, I couldn't accurately test pH, but I got a test done at a pool store on Friday and read a pH of 6.5 while my FC was virtually 0, also, I was under the impression that high FC would cause a pH test to trend up, so the fact that it was still reading low I figure it must be low. Last night I put in enough liquid chlorine to bring the pool to shock levels. I was reading 0ppm FC with an OTO test last night, so I used the calculator with a CYA reading of 73 that I got from the local pool store on Friday.

On my way home from work today I picked up some Diapers, Milk, and Borax.

According to the calculator, I needed to put in 31oz (by volume) of Borax to go from 6.5 - 7.5 with a TA of 0, so I put in 31oz (by volume) at about 5:45PM.

Dusk(9:00PM):
FC - 10.5ppm
CC - 0.5ppm
pH - Still Low (looked lighter than the 6.8 reading on the test kit again)
CH - 50ppm (thought I would check since I am dealing with a cloudiness issue)

So, here are my thoughts on these results:
1.) What is causing me to lose FC if CC is at 0?
2.) How long does it take for pH to go up after adding Borax? Does my ridiculously low pH and 0 TA cause the pH test to be inaccurate at incredibly low levels? Should I wait on the pH to go up, or just go ahead and add more Borax?

Plan for tonight:
1.) Bring FC up to shock levels, test to be sure, and then do the overnight FC loss test.
2.) Add more Borax, not sure if I should, but the low pH sucks.
 

macgulley

Well-known member
Apr 30, 2012
101
#9
Unfortunately, your OCLT will have to wait. The addition of more water (and likely organics) would render your test inaccurate. :cry:
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#10
Not uncommon for FC to be consumed and the CC not to go up ... the FC actually breaks down the CC in addition to the sun breaking both down.

You really need to get that pH in line. I thought the borax was effective very quickly, but your pH mau have started way lower than you thought. Actually getting the TA up some may help your pH issues as well.

Just keep that FC up at shock level and the filter clean and you should be clear soon.



Posted with Tapatalk ... sorry if I sound short ... hate typing on phone :)
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#11
Quick question, does the overnight chlorine loss test have to be done at shock levels?

For example, with a CYA of 75, my FC target is around 8, and shock level is around 29. Would the test be just as effective at lets say 10ppm?
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#12
Last night, due to the storm, I didn't put in any chemicals. This morning I test my chlorine levels.

FC - 10ppm
CC - .5ppm (water hardly turns pink when I add the R-003, so may be less, it is within "margin of error" to be 0)
pH - Still low

Due to the virtually non-existant overnight chlorine loss, do you think I am in the clear with regards to the algae? Is my first "shock" over? Now I just have to filter/scrub/vacuum and maintain a good chlorine level? And of course get my pH/TA in check.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#13
No the OCLT does not require shock level. FC does need to be at least 4, but doesn't have to be at shock level.

You are doing very well. If the water is more or less clear then you are done shocking. If the water is still murky you should continue shocking for a little longer. You should see a visible improvement in water clarity from day to day. If you don't there might be some problem.
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#14
I have noticed very little improvement in terms of clarity. Or I should say that I have noticed VERY SLOW improvement. I believe that the Intex pump/filter that was sold with the pool is just so inferior, that it is taking a LONG time to get all the crud out.

With algae, if I turn the pump off overnight, should the dead algae settle to the bottom? possibly making it easier to vacuum? CH is low, so I don't think that is what is causing the cloudy water.
 

Fancypants

Well-known member
May 18, 2012
88
Greensboro NC
#15
Tested pH and TA at lunch today.

pH - Still reading low, a light yellow using a Phenol Red test. I have added a whole box of Borax at this point
TA - 30 This morning I put in 1/2 of what the pool calculator told me would get it up to 80.

Should I keep TA low, so that the Borax will more effectively raise pH?
 
May 23, 2012
5
#16
What's the reason for circulating here? I have no experience with Algae (Salt pool, never had it) but I had my pool deck paved which left me with powdered brick floating in my water and it was milk for days. I finally went to the pool place and got some "Drop Down" and added that, let it circulate for a couple hours and then shut the pump off. The next morning EVERYTHING had sunk to the bottom and I just vacuumed it to waste. Cleaned the filter (replaced it actually) and then it was crystal clear 2 days later.
I"m not sure what the generic name for Drop Down is but in my experience, keeping the water circulating was the problem as my filter wasn't good enough to get rid of the fine particles.
 
May 23, 2012
5
#18
Yeah I understand why you think that's the obvious answer but in my case what I was trying to filter was a ton of smaller matter that effectively was smaller than what my filter could get so I was just stirring it all up. I strongly suggest you go get some chemicals to help with this. They make Drop Down which is the extreme case and then they have other forms that will allow matter to clump together so that your filter can snag them better.