New (to me) small pool with algae - help!

[palazzo]

Just bought a home it has a 3500 gal pool made out of fiberglass, the pump isn't marked but there is flow meter showing 40GPM the water goes into a 80sq ft cartridge filter then a 80 watt UV filter that's it.

I cleaned the pool changed to water washed out the cartridge and cleaned the UV sleeves.

in 2-3 days the green shows up, clean it up and it comes back.

The folks that sold us the house he said he never used chlorine, the pool is too small, the UV takes care of everything.

It is set to run 24/7

So much for that BS.

So I guess I need to add chlorine or the saltwater chlorine, but it appears that they don't make a saltwater generator small enough for this pool.

I know from neighbors that the source water is hard they say it 8 or 9 on some sort of scale.

So I need some suggestions on where to start and what my options may be.

Thanks in advance

 

[RobbieH]

Welcome to TFP!

I doubt UV is going to be much help unless it's an indoor pool. Someone experienced can chime in on that.

On a pool that size, I'd just use plain old bleach. You would not be hauling very much.
To get started, read Pool School in the top right corner of this page. Second, go to http://poolcalculator.com and enter your pool size and such. Don't forget to enter toward the bottom that your pool is fiberglass, source is bleach, and to use troublefreepool for goals.

You need a way to monitor your pool's chems too. Do you have a test kit at all yet?

 

[palazzo]

I'll order the test kit, so no need for a chlorine generator....interesting.

How much bleach would you suggest starting with, I measured and timed the water refilling so the 3500 gal is fairly accurate.

Also are you talking house hold bleach or what?

 

[jblizzle]

Welcome to TFP!!!

You can get a chlorine generator if you want, but you need to learn to understand the chemistry first and all of that info is available in Pool School. Your pool is small enough that you could try this method of maintenance, and just drain and start over if things get out of whack: pool-school/temporary_pool_guide

Use the calculator that Robbie linked to and it will tell you how much bleach you will need to add. Generally a pool loses 2-3ppm of FC each day, which means you would be around 11-16 oz of 8.25% plain old bleach everyday.

 

[palazzo]

Which test kit TF-100??, or do I only need chlorine & PH?

who has best price?

So keeping the solar cover on will help the chlorine last a bit longer, correct?

Doesn't chlorine break down just over time anyway?

 

[jblizzle]

TF-100 is the BEST kit available ... and it is only sold by the Dave who happens to own this forum as well (although there is a West Coast distributor of it as well, Dave is on the East coast). Often people balk at the price of the kit when it cost more than their pool, but it really is the best tool out there. If you already had the pH test, the TF-50 is a little cheaper, but you get less of the needed reagents.

The cover will help protect some of the FC, but you really need to use some stabilizer (CYA) to protect the FC from the sun as well.

Chlorine (FC) is lost to 2 things: the sun and stuff in the pool. Using CYA helps protect it from the sun.

Please read at least the first few articles in Pool School to get you started:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

 

[palazzo]

using the pool calc inputting 3500 G and fiberglass etc when I hit calculate nothing happens

Just a bit confused how to get it to calculate.

I'm waiting for the test kit, but wanted to start adding chlorine now.

So I guess what I'm asking at this point is how much to add initially ?

thank you

 

[Bama Rambler]

What did you put in the rest of the cells for Now and Target?

Also, did you put a comma in the gallons? If you did, then there's your problem.

 

[RobbieH]

It auto calculates. Put in your current test results in the left column, and your desired goal in the right column. Then in the body the amounts will be populated. If you hover over the amount suggested, it will tell you in the top white box how much to add.

Don't forget to set everything in the bottom yellow rectangle labeled "Suggested Goal Levels". Trouble Free Pool will be your source of goal levels.

 

[palazzo]

ok, I thought I only needed to input the gal. and the bottom items.

I entered FC 0 goal of 4 it gave me 29 oz.

 

[DorsalSpine]

ok, I thought I only needed to input the gal. and the bottom items.

I entered FC 0 goal of 4 it gave me 29 oz.

That is correct for 6% bleach. You may find it at higher concentrations as well. I use liquid pool shock which if you read the label is 12.5% chlorine. Don't forget to select the concentration when you use the calculator.

 

[palazzo]

thanks I saw that already, only had about 10 oz on hand added that need to go get more later today.

How soon after adding can we go in the water?

Any guess how long before the algae goes away?

 

[jblizzle]

If you have algae you need to follow the SLAM Process which requires much higher FC levels than 4ppm and will likely take a least a few days to clear up assuming you have one of the recommended test kits.

 

[DorsalSpine]

thanks I saw that already, only had about 10 oz on hand added that need to go get more later today.

How soon after adding can we go in the water?

Any guess how long before the algae goes away?

You can swim in water with FC up to the shock level appropriate for your CYA level. Give it 30 - 60 minutes to mix and you will be fine.

Read the SLAM process as was suggested earlier.

 

[palazzo]

I reading all I can, thanks for your help.

Anyone have an idea on using the UV sterilizer with a normal level of FC when things get squared away and I can test the water in few days.

I read online that it works, then I read it breaks down the chlorine.

Confusing as usual.

 

[jblizzle]

There is no need for UV or ozone in private outdoor pools ... waste of money. Chlorine will do everything that needs to be done and the sun provides plenty of free UV.

 

[palazzo]

I understand what you're saying, but

Well it came with the house, so doesn't cost anything but 80watts of electric.

Will using help clarify the water and in turn will i use less chlorine.

 

[jblizzle]

You still need to maintain the recommended levels of FC regardless if you use the UV system or not. And as you pointed out, the UV system will break down some of the FC and require you to use more.

So by using it, you are going to have to add more FC and it will cost you extra electricity ... for no net gain.

 

[Smykowski]

If it's an outdoor pool, you're getting more UV radiation than you'll ever use for free.

 

[chem geek]

I understand what you're saying, but

Well it came with the house, so doesn't cost anything but 80watts of electric.

Will using help clarify the water and in turn will i use less chlorine.

It won't be of benefit and if it's powerful enough it will actually consume more chlorine -- it will act like sunlight which breaks down chlorine. You could disconnect it (power it off) and get your water into shape and see what kind of chlorine loss you have overnight with the pump running. Then do this again on another night but have the UV connected (powered on) and see if you notice a difference in the overnight loss of FC. If you don't see any FC loss, then the UV is so weak as to not be bothered with it and if you do see FC loss then it's powerful enough but you are just using up more chlorine.