Starting from scratch, need some advice

[Bender]

Purchased a home in Phoenix constructed in 1985. This is my first pool and I don't know much about pools in general or the one at this house - math using the kurtzwater.com volume calculator and a tape measure has me thinking it's about 14,000 gallons. It's appears to have a Hayward Pro-Grid D.E. filter of unknown size (~39.5" from the ground to the top so maybe a DE4820?) and a 1 HP 1.65 SF A. O. Smith Centurion pump. Prior owner left no instructions of any kind and had turned off the pump timer (thanks)! I've been running the pump a couple hours every night with the timer. I've added some chlorine (bleach) but I was wary of doing too much until I had a test kit. On sweeping the bottom I noticed something collecting there (algae?). Test results:

pH 8.5-ish
FC 2
CC 3.5
TC 5.5
TA 150
CH 660 (this seems way out of bounds, did the test twice)
CYA no reading (water clouded halfway between the 100 and bottom of the vial on the TF-100 test).

Questions:

1. What do I need to do to bring the chemicals in line? Do I need to SLAM or should I start adding things as needed?
2. If anyone can confirm that it looks like a DE4820 or knows a way I can tell for sure, that'd be great.
3. Filter is running at 22 psi. Not sure if it needs a backwash. Downloaded the ProGrid manual so maybe I can figure it out from that.
4. I'm unsure how long the pump needs to run daily. Pointers appreciated.
5. Is that algae in the bottom? Will fixing item 1 bring everything in-line with that?
6. Anything else I should be aware of?

--
Edit: further research has me thinking I need to do the following:

1. Determine why the pump pressure is so high. Backwash, add D.E. (Where do I backwash to? City sewer? How much D.E. do I add)?
2. Get pH within range (muriatic acid?)
3. SLAM

 

[pwrstrk]

Welcome to TFP !!
Yep you need to SLAM the pool with a CC of 3. How does your water look ?
My question for you. When you did the CYA test, when did the black dot disappear ? If you had zero or close to zero the CYA tube would be full and still see the dot. If the dot disappeared at 100 then your CYA level is 100 or higher. If it is that high then your looking at replacing water to get that level down. We need to know the correct CYA level to determine your SLAM FC level.
Your correct on lowering your PH with acid. Get it down to around 7.2 for the SLAM process.
As for your DE filter you need to know what size so you can add the right amount of DE. Can you post a pic of it or get a model number ? As for the pressure, you need to know what the clean pressure is to determine if 22 psi is high or not.
Take a look at this for pump run time pool-school/pump_run_time

 

[Isaac-1]

Just to follow up on that, being in Phoenix you may have the option to have reverse osmosis treatment done to lower your CYA as an alternative to water replacement.

 

[Bender]

Yep you need to SLAM the pool with a CC of 3. How does your water look ?

To me the water looks pretty good, apart from the accumulation on the bottom (the left side is where I've swept with the brush, the right side shows the accumulation which I assume to be algae). Very clear water and it looks pretty blue to me.

My question for you. When you did the CYA test, when did the black dot disappear ? If you had zero or close to zero the CYA tube would be full and still see the dot. If the dot disappeared at 100 then your CYA level is 100 or higher. If it is that high then your looking at replacing water to get that level down.

I could not get a reading because it clouded up higher than 100. My guess would be halfway between the 100 and the bottom of the tube - but since the markings didn't look linear I don't know what I'd estimate it at. Certainly more than 100 (so, off the SLAM chart on the site).

As for your DE filter you need to know what size so you can add the right amount of DE. Can you post a pic of it or get a model number ?

I don't know if you could see the attached pictures on my original post but here is an image including the filter. I am guessing based on size and the torn up label that it's a Hayward Pro-Grid D.E. model number DE4820 but that's just based off of measuring the size and comparing to a Hayward Pro-Grid manual and pictures online.

being in Phoenix you may have the option to have reverse osmosis treatment done to lower your CYA as an alternative to water replacement

How complex is this? What's the approach (buying equipment, hiring someone to come in)?

 

[pwrstrk]

Your water does look pretty good. The reason I said to SLAM was CC of 3.5. That test result was from the TF 100 right ?
The CYA needs to be addressed. That will also help with the CH unless your fill water CH is high also.
I can't really help you to know for sure what size filter that is. Somebody else should be able to, unless your confident on that model number. How much DE does it call for, for that model number ?

 

[Bender]

Your water does look pretty good. The reason I said to SLAM was CC of 3.5. That test result was from the TF 100 right ?

Yes it was. I'm pretty sure I did the test right but I'll probably do it again in a few days to ensure I did.

The CYA needs to be addressed. That will also help with the CH unless your fill water CH is high also.

Yeah. I have no idea how it got so high. Perhaps the prior owner added a bunch before moving out? I'm new to all this so I don't know exactly what I'm doing in regards to backwashing and draining and then refilling. Perhaps I should test the CH on the tap water to see where it rates before I take any water replacement actions.

I can't really help you to know for sure what size filter that is. Somebody else should be able to, unless your confident on that model number. How much DE does it call for, for that model number ?

My confidence isn't too high, I'm going off comparing pictures on the Internet and measuring the size of the unit. The manual recommends 6 LBS of D.E. for the DE4820 model. The amount of D.E. varies quite a bit based on the size of the "Pro-Grid" models so I'd hate to be wrong.

I am wondering at this point if I should enlist a professional to help me get started with all this or if I can really do it all myself without making things worse.

 

[pwrstrk]

No need to hire somebody. There's lots of good people hear who know what they are doing. We'll get things straightened out for ya.

 

[Richard320]

Welcome!

We can walk you through this.

That pump pressure does seem a little high, but it could also be a bad gauge, or it could just be where your system runs. If the needle goes back to zero when the pump is off, the gauge is probably good. You should do a full teardown and thorough cleaning just so you know what your baseline pressure is. Backwashing alone will not remove everything. For all you know, the filter may look like this inside:

[center:fkmvmbfx][/center:fkmvmbfx]

You have a backwash hose attached to the bottom of the push-pull valve. I imagine the previous owner discharged it somewhere within that reach. There are probably city ordinances prohibiting you from discharging it into the storm drains, which leaves you with lawn or sewer. Hint: I use cellulose DE replacement, and backwash it onto the lawn. The lawn seems to like it. DE won't hurt the lawn, but when it dries out, the dust can be an inhalation hazard.

The CH level is actually lower than I would expect for where you live. extended-test-kit-directions-t25081.html has instructions for testing with really high CH and CYA.

That high CYA level is also easy to get. One of my better pieces of writing, if I say so myself

We'll take a 16000 gallon pool, because that's what I have. On a fresh fill, prominent national pool chain recommends 2.5 pounds pf stabilizer per 10,000 gallons, which works out nicely to 4 pounds which brings CYA to 30.

With an average loss of 2 PPM/Day or 14 ppm/week, I'll have added 8.6 PPM/CYA if I used trichlor pucks perfectly. And they recommend a weekly "shock" of dichlor between 5 and 10 FC.... 2-3 oz per 10,000 gallons. Split the difference; I'll add 4 oz. CYA went up another .9.

So..by the end of week one, I have added 9.5 more CYA. It is now 39.5. Mimimum FC for that is 3, so I'm probably okay.

Week two, up to 49 CYA.
Week three, 58.5. Minimum FC should be 5, but they recommend 3 as ideal, so the pool looks a bit hazy. So I'll toss in a little extra dichlor "shock" to jack FC up to 10. Which adds another 6.4 CYA. Keeping count? We're up to 64.9 now.

That caught the algae just in time.. we had two weeks of good luck. A steady diet of pucks and 4 oz. "shock" each week only added another 19, up to 73.9 now.

Week 6 it started looking funky, so we "shocked"it once again. CYA is up to 99.3. But minimum FC to keep algae at bay is 8, and we're still holding things to 3, because prominent national chain's preprinted sheet shows that as ideal. So algae got a toehold and the pool has a bit of a tint. So we throw two whole bags of dichlor in which jacks it another 7.6 by the time week 7 is over, we're at 116.4, because we had pucks in the floater the whole time.

So...in 7 weeks, from 30 to 116.4. Let's say there are no more algae outbreaks because they sold me a huge bucket of phos-free and another of yellow-out monopersulfate "shock" Nothing but the pucks and the extra 4 oz of dichlor "shock" weekly. So the next 7 weeks added 66.5, which brings the total to 182.9 CYA.

Now if we didn't understand this and things looked a bit hazy, we might throw an extra puck or two in the floater every couple weeks, which will drive it over 200 easily.

High CYA will make it difficult to SLAM. So a drain and refill is in your future. How much depends upon the CYA level. The SLAM can be done without too much trouble at 50; lower is easier. But since the water isn't green and murky, I think it should go fairly quickly, which will allow you to do it at a higher CYA level of 50 or so.

There's no reason to pay money to hire a pro. You have the Cadillac of test kits as well as plenty of people here willing to help, and it's not the busy season, so this thread won't get lost.

 

[danacc]

Welcome!


Yes, that DE filter looks just like the Hayward Pro-Grid DE series. Does the label say "Grid DE" below Hayward? It looks like it might. Based on the height you posted and the way it is seated on the ground, it is the DE4820. There are 6 inches of difference in height between this model and the one bigger or the one smaller. You can be confident you have the DE4820 and go with 6 pounds of DE.

As previously posted, your first order of business is to get your CYA down. This can be done through reverse osmosis or by draining and refilling. You'll need to hire somebody to do the reverse osmosis; it requires highly specialized equipment and is unavailable altogether in most places. Phoenix is one of the places you can find this service. Don't expect it to be cheap. You'll end up with pool water that has no CYA and no CH. You will lose a percentage of pool water in the process, and need to fill to make up the difference. Before going this route, do some research to understand it better.

Your other choice is to drain and refill. You're going to have to drain a lot based on your CYA reading. To get a better ballpark on your CYA level, try running the CYA test with a mixture of half tap water and half pool water. Your tap has no CYA. Test the mixture, and then double the result to estimate your pool water CYA level.


You can lower the pH and bring up the chlorine level now if you decide not to start draining right away. Otherwise, I'd drain and refill ~50% before adding any chemicals. Otherwise, half of what you add will be immediately drained, anyway. Be prepared to drain and refill a few times. Test the CYA after each refill so you can adjust the amount to drain as it comes down. Also, test your tap water and post those results. You may need to watch and adjust pH or CH depending on what's coming out of the tap.

 

[Isaac-1]

I see no point in trying to SLAM until you get your CYA under control. As has been mentioned RO treatment is only available in select areas, mostly places with high CH and expensive fill water, even then it is often questionable if it is economically feasible, if there are multiple RO services in Phoenix I suggest getting quotes from all of them as there is a LOT of variation in prices charged ranging from expensive to insanely expensive. One advantage of RO over water replacement is it can lower your CH to lower than your fill water levels (not sure what those are for you). There are a variety of RO services out there, and depending on the type of equipment they have different types and amounts of water prep may need to be done to the pool before they can treat it (things like removing all chlorine may be necessary). Some services use large trailer mounted RO systems often powered by their own generator or engine which can process a typical residential pool in 8-12 hours, others use much smaller cart based units that plug in electrical outlet and take several days to process all the pool water.

Ike

 

[Bender]

Thank you all so much for responding and helping to demystify this pool situation. I can't tell you how comforting it is to have experts on the job.

One of my better pieces of writing, if I say so myself

I agree, quite well-written. Thank you for this, this situation is so much easier to comprehend with a narrative versus some perplexing test results.

Does the label say "Grid DE" below Hayward?

Yes, it does. I'm going with this as a DE4820 and following the instructions for that filter. Thanks for the verification.

My to-do list looks like the following:

1. Follow advice posted by danacc to get an actual CYA reading and also see the condition of tap water for a potential drain-refill to see how it will affect the water chemistry.
2. Research reverse osmosis and call around to get quotes.
3. Figure out how to open the filter up and visually inspect the condition inside.
4. Once an approach (reverse osmosis/drain-refill) has been selected and completed, start the SLAM process.

I'll let you all know the results in here as things progress. Thanks again!

 

[pwrstrk]

Sounds like a plan. Keep us posted.

 

[Bender]

I've continued this thread over here now that I've done the drain and refill.