Coagulant in recently resurfaced Diamond Brite pool to reduce initial cloudiness

[Moi]

Hello,

I have a 15 year old in-ground 10,000 gallon pool which has been resurfaced with Diamond Brite, replacing the Marcite finish. I live in West Central Florida, about 10 miles from the coast. Until recently it was professionally managed, LOL.

The pool was filled, pump was started, DE filter recoated, acid and sequestering agent were added per the refinishers instructions. Daily brushing started on the first day 8/19.

I expected the pool water to appear milky, which it has, and to remain so for a number of days as the new surface cures and daily brushing takes place. Is there any reason I should not add a coagulant to aid in the filtration process?

Thanks in advance for any advice pro and con. BTW, I am new to the forum.

Peter B. (User Name: Moi)

 

[chem geek]

Welcome to TFP!

We generally don't add extra chemicals that are not needed as they not only cost more but can have side effects. Your cartridge filter should be able to remove the calcium carbonate "plaster dust" without the need for clarifiers/coagulants/flocculants. If it bothers you, you can increase your pump run time. The amount of plaster dust should decline as the pH rises; follow the instructions from your pool builder and note that next time you have to resurface the pool you can avoid plaster dust and have a stronger finish by using a Bicarb Start-up.

 

[Moi]

Thanks Chem Geek,

It was just a thought on my part that perhaps it would speed up the process. The pump is running full time except for a few short breaks each day. It runs two hours on then one off all day long right now. This is day two since pool was refilled. Allowing the system to rest for brief periods results in a lower filter pressure and better flow when the pump restarts. It is as if sludge buildup in the filter falls to the bottom of the tank exposing cleaner DE.

Last year when I had a major particulate problem, I was cleaning and re-coating my filter every day which was a real pain, but soon discovered that periodically shutting down the pump for a while meant I could go several days without have to clean and re-coat the filter.

Peter B.

 

[Moi]

Yesterday I had to clean and re-coat the filter, the return flow to the pool had reduced significantly. The water is not as cloudy. Also the installers instructions required 2 1/2 pounds of Splash Conditioner to be added, this was done.

Today a water sample is going to my local pool supply store for iron and copper analysis. The instructions say that there should be none in the water before any chlorine is added.

 

[Moi]

I live in Florida about 70 miles North of Tampa, and as you may be aware Tropical Storm/Hurricane Erika is heading our way and we will get dumped on rain wise; maybe even a few cats and dogs thrown in for good measure. We could get a couple of feet of rain all told added to my pool over a few days. It will overflow of course, but the extra will screw up my chemistry. We are currently into day 9 after startup and I have my pump timer now back on a more normal schedule instead of 7x24.

Are the any precautions I should take before the storm, or is there anything you can recommend for the after period other than returning the chemistry to normal? I am currently maintaining Cl at 1 to 2, pH at 6.8 to 7.2, CH at 300-350 and TA at around 30 to 40. These values are in accordance with the resurface contractor’s instructions.

Any advice you can give would be appreciated.

 

[Sandra B]

Hi Moi. Welcome. Do you have your own test kit? I'm asking because Cl at 1-2 is awfully low, especially if you put the 2.5 lbs of stabilizer (CYA) in. At 10,000 gallons, 40 oz of CYA will bring to you about 30 CYA, if you started with fresh water. Using the Chlorine/CYA chart here: Pool School - Chlorine / CYA Chart tells me that your Cl should be between 2 and 4, and never below 2 or you risk an algae outbreak. Do you know for sure what your CYA measurement is?

The test kit recommended on this site is a drop-based test, and it's easy to use and really handy. Here's one website you can get it from: TFTestkits.net . I have the K-2006, which is a smaller kit and for your pool, probably all you need as well. Pool stores just aren't consistent or reliable with their testing, so we generally do our own. There isn't really much you can do to prevent the rain from diluting your water, but it's generally going to be an easy fix to get yourself back in balance. Usually you need to adjust your pH, and adjust your chlorine. Hopefully you don't get a lot of dirt or debris washed into the pool. If you do, just keep your chlorine on the high side of normal and filter/net it all out.

The beauty of your own test kit is that you can be out as soon as the storm passes, grab some water and test, and be balanced again in an hour. Good luck, and stay dry!

Sandra

 

[Moi]

Hi Sandra,

Thanks for the reply.

I have upgraded my test kit from a basic OTO type that did not do very much to a new Taylor K-2005C test kit. I figured that because I now have a better than new pool, I might as well start off with the good tools. I also periodically take samples to two different pool supply places, just for comparison purposes.

The 1-2 Cl^- level is what was recommended by the resurface company for the 30 day startup period with no shock for at least 3 weeks, but I will probably raise the Cl^- level over the next few days as it looks like we could get a foot or more of rain from Erika early next week. I will be checking my CYA today; the pool was initially filled with city water.

Fortunately, even though it is an outdoor pool, it is inside a large screen enclosure, so I should not have to deal with much debris, only rain water. Unless I get a 2x4 or a flower pot come through the screen. I normally move all items that are not fixed down up close to the house, we have a large lanai area and about 600+ sq feet of it is under the roof.

I will keep you posted.

Peter B.