Slight Green Tint

by Lonnie

My pool still has a green tint and is very cloudy. With goggles you can see about a foot. I have a 14x28 in ground. 3-6 ft deep. I have a Hayward 300lb sand filter with fresh sand. Ive shocked it with about 30 lbs over the past month. I've vacuumed, back washed several times per day. Just not sure what's going on. Please let me know what you think. I've listed my levels below. Thanks for any advice. CYA 54 Free chl 14.7 PH7.5 Tot alk 91 TdS 500.

Thanks for the question Lonnie. Your readings seem fine. The CYA is starting to creep up at 50ppm. The range is 30 - 50ppm so keep an eye on it and do a partial drain and refill at 60ppm. You don't want to wait until it get to 100ppm. That will require a much larger refill.

Your pool is about 15k gallons. Is that right? It's important that you understand this part of pool maintenance. Shock is not a product. It's not something you buy, it's something you do. It's maintaining a FC level of 12ppm until the algae is dead. This can be accomplished with liquid chlorine or even grocery store bleach. The "shock" at your pool store has virtually no special properties to it. They're simply either stabilized or unstabilized chlorine.

That being said, what you need to do is to get AND keep the chlorine above 10 - 12ppm for a period of time. You'll need to manually dose the pool with chlorine to keep it at 10 - 12ppm. Make the adjustment at night, then retest in the morning. Be sure to have the pump running 24/7 and backwash once per day. You can go up to 15ppm, but no higher. Anything after that and you're wasting money and chemicals.

You'll know this is working because the pool will go from green to a white/grey cloudy and the chlorine will begin to hold better. First you may lose most of the FC, then 2/3, then 1/2, and so on. Once you only lose 1 - 2ppm of chlorine 8 - 10 hours after the last application you know the algae is dead. Now it's just a matter of filtering and backwashing once per day. Broadcast the chlorine around the perimeter of the pool and brush well. This will loosen up any algae adhering to the walls and bottom. Try to vacuuming once per day right before you backwash. Maintain a pH of 7.0 - 7.2 during the shock process. Chlorine works better at a lower pH.

You should also get your water tested for metals. If it comes back positive you'll want to use a good metal sequestrant. Jack's has a good line. You can get it on Amazon or possibly WalMart. Look for the HEDP chemical in it. You must also be sure the filter is working perfectly. You can't filter cloudy/green water with a non-working filter.

If you feel your situation is more complex than this, I do phone consultations. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias. If you purchase a personal phone consult you'll get all 3 eBooks for free.

Pool Consultation

Clear Blue Pool eBook

How To Clear Up A Green Pool eBook

Swimming Pool Resources

Hope this helps and have a great Summer.


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Green Pool

by Vikki

I have a green pool and I am wondering when it is just best to drain the pool and start over with fresh water.

Also, I am not sure of the plumbing equipment and I can not get the water flow to run thru the system. I have a sand filter.

I have concluded that a lateral is broke on my sand filter to my inground pool. What is the best route to take, fix the lateral, either myself or have someone do it or replace the filter. the filter is 30 yrs old.

Thanks for the question Vikki

If you feel comfortable doing it yourself and have all the parts you might be able to. It's pretty straight forward. You simply scoop out the sand, replace the stand pipe and laterals, then add the sand back.

The laterals screw in like a light bulb. The trick is to get the standpipe to stay while filling with sand.

You also want to fill the filter about 1/3 - 1/2 with water. This will disperse the energy of the sand while filling the filter.

If you're unsure about anything, the best recourse is to hire a professional pool tech.

It's hard to say whether the pool should be drained or not. I'd like to have your complete chemical readings:

Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper).
It makes troubleshooting much easier and the process of clearing up your pool will go much faster. You can get this done at your local pool store.

Green Pools

Without these numbers I'm just guessing at what the problem is.

Concerning the low pressure on your filter, here are some pages with the same question as yours. They're not worded the same but the troubleshooting tips are identical:

Sand Filter Pressure Increases And Low Suction

No Backwash Or Rinse Pressure On A Pool Sand Filter...

My Pool Sand Filter Has Low Pressure..Low Psi & Multiport Valve Is Leaking..

Get back to me with the chemical numbers and I'm sure I can help.

Hope this helps and have a great Summer.


Comment By Vikki

free chrlorine =ovr 4.0 ppm; total chlroine= ovr 4.0; combined chlorine= 0.0 ppm; pH=UNR6.5; hardness= 0ppm; alkalinity=0 ppm; cyanuric acid= 10 ppm; cooper=0.0 ppm. Did not run iron or total dissolved solids.

The pool company that I am using is stating that to replace the filter I could use a 24 inch and i know mine is bigger but not certain if they are just trying to sell me one that they have already in stock or will it work.

I am also not certain how many gallons are in my pool. the deminsions are as follows: (this comes from my measurements for a polynesian pool vinyl) 10.5 feet deep ; 45 ft long; 19 feet across (ranging from 5 ft on the shallow end to 10.5 on the deep end).

What is your price on a sand filter 24 in and the next one bigger. Will my pool people be will to install it reasonably if I order from you and have them install it?

Thank you so much for your help.


Thanks for the readings.

I'd encourage you to get a Taylor FAS-DPD K-2006 pool test kit. It's the best on the market. A TF100 kit will also work well.

Pool Water Testing

Water Testing Kit

The pH is a bit low, along with the alkalinity and cyanuric acid (CYA). You can bring the hardness up to around 100ppm. You have a vinyl pool and the hardness is mostly for plaster/concrete pools The pool size is 49,000 gallons, a pretty good size.

I'd first focus on the alkalinity. Get that between 80 - 100ppm, 120ppm being the top. 2.5 oz. of bicarb will raise the total alkalinity (TA) of a 20,000 gallon pool 10ppm. Being that yours is 0, simply double the amount. You'll want to start with about 1.5lbs. of bicarb. This is baking soda that you can get at your grocery store for 1/3 the price. Don't use Alk Up or something like that. It's all baking soda.

Add the bicarb in the deep end with the pump off. Wait about 3 - 4 hours, then turn the pump back on and wait for 1 turnover over of the water, about 8 hours, then retest and make another adjustment if needed. Don't make a slurry with the bicarb. Just put it in. Make the adjustment in the evening then retest in the morning.

Pool Alkalinity

Total Alkalinity

Once the TA is in line, you'll shock the pool using Dichlor chlorine. This is a stabilized form of chlorine that will put CYA into the pool. Be careful when using Dichlor as it can get out of hand quickly.

For every 10ppm of chlorine added with Dichlor, you'll raise the CYA by 9ppm. Keep the filter on during the shocking process, 24/7.

The CYA needs to be between 30 - 50ppm. Shock it with Dichlor in the evening and retest in the morning. Keep doing this until you reach the 30 - 50ppm CYA. Once this is reached, switch to regular liquid chlorine for shocking.

You want to keep the chlorine level above 10 - 12ppm for as long as you can until the water clears up. The water color will turn gray, then white. Keep shocking and testing, each time allow 1 turnover. You'll notice that initially the retest will show there's no chlorine. The chlorine is consuming the algae.

Keep shocking and retesting. Soon you'll notice the chlorine is holding a little bit more.

You'll go from 12ppm of chlorine down to 0. Then 12ppm to maybe 4ppm. Then 12ppm to 8, and so on. When the chlorine holds well, you'll know all of the algae is dead. Backwash once per day.

Green Pools

Test the pH as well. After the initial dose of bicarb for the TA, the pH may come up a bit. If it's around 7.2 or so, just leave it alone. It'll come up on its own.

Don't get any clarifiers or algaecides to clear the pool up. These are preventative measures but don't address why the pool is green in the first place.

I'd suggest getting the same size filter, or even bigger. With pool filters, a little (but not too much) bigger is always better. If you can, get a cartridge filter. They're better than a sand filter and much less hassle than a DE filter.

Swimming Pool Filter Cartridge


You can order from Amazon and have it shipped to you, if that's what you wish. A good one is Jandy 460 Sq Ft CL Series Cartridge Filter CL460. You can look at the specs. and product reviews.

If you want to go the Amazon route, you can go to this page, then click the Amazon link at the top of the page:

Pool Store

This way Amazon knows you went to them through my site. This isn't just pool products. Once you're on Amazon you can go wherever you want and I get credit for it, as long as you go through my site first. I give 10% to the Shriners Hospital for Children.

That's pretty much it for now. Anything else just email back or if you want to have personal assistance, go to the donation page. You can leave your number and I'll call within 24 hrs.

Contact Me




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