To drain or not to drain pool with high CYA?

[stevemac213]

Hi there. New to this forum and have a question...I drained my pool a few months back because of high CYA but apparently didn't take enough water out since it is too high once again, (about 200).

My question is...should I drain it now and keep it up over the winter, or just let it go green and drain it come springtime, and start over?

Any and all responses are greatly appreciated...thanks.
Steve

[PoolDoc]

What size pool? What type? (Concrete, vinyl)

You probably do NOT want to let it go green -- the high CYA will probably be biodegraded to ammonia. It may subsequently be converted to nitrates or nitrogen gas, but if it stays as ammonia, you will have a horrendous spring start-up problem.

[stevemac213]

Thanks Ben. I filled in all my pool info but it is not showing up for some reason?

It is a concrete 27K gal in-ground pool.

It is already turning green since I've ignored it for the past week, (since pool season is over). Do you think I should drain it now rather than wait? I was told to wait because the CYA may go down over the winter and therefore I would not have to drain as much? If I did drain it now, how much should I take out...all of it or no?

Thanks!

[PoolDoc]

Read the Best Guess page, linked in my blue signature block -- you *can* operate the pool with high CYA.

If you're going to let the pool go green, I'd wait till spring to drain and refill. The reason is, if you end up with ammonia in the water in spring, you'll probably want to drain 100% -- but there's no way we've found to determine exactly what the bacteria will do in YOUR pool, so right now it's just a crap-shoot whether you end up with CYA => nitrogen gas OR CYA => nitrates OR CYA => ammonia.

If you don't want to risk it (and algae stains, etc) by abandoning the pool for 6 months, you need to clean things up NOW -- use plain household bleach in 10 gallon doses till you read an OTO 'orange' level. AND . . . order a K2006 kit so we can get accurate test results, and work out a 'next' step.

[stevemac213]

Ok, draining it now but I only have a small pump so may take a couple days. Is there anything I should be doing while it's draining? (i.e.. sweeping sides/bottom, etc)

Thanks Ben.

[PoolDoc]

Yeah, what you said.

You don't want stains or algae to dry on the sides. Using a hose with a nozzle is probably the easiest solution.

[stevemac213]

Ok...makes sense.

How much do you think I should drain? (50%....75%....100%)?

Thanks.

[PoolDoc]

Either drain it all, OR purchase a K2006 kit, and let us walk you through a high-range CYA test to see what your actual levels are. CYA test results from strips are too unreliable to depend on.

[stevemac213]

Actually, I do have a K - 2006 test kit...that's where I got the high CYA reading from. It was past 100 when I tested it with straight pool water so I did 50/50 pool water/tap water and that's how I got the reading which was closer to 200.

Any help you can provide is much appreciated.

Thanks.

[PoolDoc]

If the 200 ppm is valid, you probably want to drain 3/4 (to 50 ppm) if you are going to use bleach next year. If you are going to use trichlor (which adds CYA) you may want to drain more.

[stevemac213]

Ha ha....exactly. I'm not sure how accurate it is because I feel that the reading would change every time I did it, mainly because I'm so new to it.

I am definitely doing bleach...trichlor and dichlor is what got me into this mess.

I was thinking about 75% as well, which is what I thought I did the first time I did this, (about 3 months ago), but I guess it wasn't enough.

Thanks.

[stevemac213]

Ben, can you pls tell me if I will need to Slam it when I refill it or do I just add chlorine/bleach?
Thanks.

[PoolDoc]

Add 1 - 2 gallons of bleach every evening, till full. If you detect the slightest bit of 'green' while filling, add 4 gallons. Begin running your pump and filter, as soon as you can prime the pump, but not till the bottom of the pool is covered in water. (You don't want a jet of water hitting the pool surface directly -- depending in your water, doing so can result in stains and/or erosion.)

Likewise, avoid having fresh fill water come into direct contact with the pool surface. If there's any reason to suspect metals (iron?) are present in the fill water, add a liquid stain / scale treatment as you fill -- do NOT over dose. Dose for the water present; not for the what will be present when the pool is full.

[stevemac213]

Ok thanks Ben. Do you mean add 1-2 gallons every evening while filling it up? Not sure how long it'll take to fill but I imagine it'll be a lot quicker than emptying, since I'll have 3 hoses going in....so may take only 1 or 2 nights.

Prime the pump....hmmm. Does that mean when the water gets above the skimmer level? Also, do I need to clean the filter and if so, when?

Sorry for dumb questions but I'm a newbee.

Thanks again.

[PoolDoc]

Yep, bleach every evening.

If you're new to pools, just start the pump when the pool's full . . . but if you've never started the pump from empty pipes before, you might see if someone can show you.

[stevemac213]

Ok, what about cleaning the filter....should that be done now, or after it's filled...or not at all?

Thanks.

[PoolDoc]

What type of filter do you have?

[stevemac213]

It is a Purex Triton Cartridge Filter CC320P. I cleaned it a few months ago...the cartridges were black.

Question...I put all my info in when I signed up but not sure where it went...any idea?

Thanks.

[PoolDoc]

You should clean your cartridges -- how-to here: Cleaning-your-Cartridge-Filter-without-Damaging-It! (http://www.poolforum.com/pf2/showthread.php?18044)

No idea about the data.

[stevemac213]

Ok, cleaned the cartridges and let them soak in TSP overnight. They look good and got rid of lots of green...will I need to do this again after I fill it up and run the pump, due to algae that was in the pool?

Have drained more than 3/4 and have noticed some black spots on the bottom and near the stairs...looks like black algae? Thinking about draining it all.

[PoolDoc]

Scrape the spots with your fingernail, then smear the crud on a white 3x5 card (or similar) -- black algae smears dark green.

If it *is* black algae, I'd recommend pressure washing first, and then pouring plain household bleach on all spots. Wait till late evening, and then pour bleach liberally over all spots

Be careful, when pressure washing, to NOT strip the plaster. Old or soft plaster can't take a lot of pressure. Also, try to refill ASAP -- being dry is BAD for plaster, especially old plaster. You're in California -- lots of sun & dry air. You may want to set up a couple of sprinklers or misters on a timer to keep the pool walls damp.

[stevemac213]

Thanks Ben. I really don't want to pressure wash it because it is too old, (1986). I know it needs re-plastering but want to try and get a couple more years out of it. I did what you said and it is definitely black algae.

Would it hurt the plaster to pour bleach directly on the spots? I heard that you can also rub a 3" Trichlor puck on them. I am going to try and work on them now and then start the refill. Should I be pouring bleach in at nighttime when refilling, even though the pump is not running?

Thanks again.

[PoolDoc]

I'd use bleach, not trichlor. Trichlor is acidic, and if you get enough on the spot, will damage the plaster. (Doing in a pool that's full is much less risky.)

Bleach will not damage the plaster, as long as it has no organic binders or materials present. With an old pool, that shouldn't be a problem. I'm not sure if acrylics or latex binders are being used in new plaster.

BUT if your plaster is as old and deteriorated as your concern implies, do NOT let it dry out.

[stevemac213]

Well, I did all this before your reply since I am in the process of refilling and trying to move fast. I used a trichlor puck and it wasn't too bad...yes, it left some marks but there are lots of marks already. I was contemplating getting it re-plastered while it was almost empty but can't afford it right now so trying to get a couple more years out of it.

It is dried out because it took so long to drain...I probably should have rented a pump like I did last time and drained and refilled it fast. What do you think will happen now that it is dry and I am refilling? This pool is killing me.

Thanks.

[PoolDoc]

What do you think will happen now that it is dry and I am refilling?

Dunno. Letting the plaster dry doesn't always cause problems. All you can do is cross your fingers and hope for the best.

[stevemac213]

I certainly will....and pray as well.

Should I put in a gallon of chlorine tonight, even though the pump is not running or should I wait till it is full to shock it?

Thanks Ben for your timely replies.