How to approach restarting DE Filter in heavy green algae pool

[plnewb]

Given I just cleaned out the grids in 48 sqft DE Filter, before I turn on the pump, should I pour 4lb of D.E. slurry directly into the base of the filter body, seal it up and then turn on the pump, instead of pouring it down the skimmer?

I am used to mixing the D.E. to form a slurry and then pour it down the skimmer but this is a heavy green algae pool and I have concerns that I might corrupt the filter if I apply that procedure.

I cannot see a few inches below the top of the pool but I manually skimmed off debris, everything that was floating. There's a Hayward pool robot, it was covered in heavy green algae. I cleaned it using a hose and let it sit in the sun one full day.

Context:

Long time lurker, first time poster. I am nursing my aunt's heavy green algae pool back to health. I'm no pool tech but maintain my own pool. My uncle passed last month and turns out he used to take care of the pool, so no one was caring for it for 2, probably 3 months. When I dropped off my aunt from dialysis I noticed that the pool was heavy green algae. I added 1Gal 10% acid to reduce the pH and poured 4x 1Gal of 10% Cl at the four corners of the pool and used the brush to mix.

To my surprise, the next day, nothing had changed and that indicated the water wasn't turning through the filter.

I took the FNS 48 sqft DE Filter casing apart, washed off all the DE and green algae off it, but now I am lost what to do next - I've never faced this level of contamination before (for my own pool, backwashing is sufficient) so when I restart the DE once a year, my pool water is clean and sanitized unlike this mess

 

[HermanTX]

Welcome to TFP
One idea is to bypass the filter. Do you have a Multiposition Valve on the DE filter or just a simple backwash plunger?
If you can put the MPV in recirculate position, then add your chlorine by following SLAM Process. Do you know your CYA level? Run like that for a day or 2.

This will start the process of killing the algae, then you can manually vacuum to waste if you want to bypass the filter that way or you can just scoop out the dead algae but that only gets so much before you have to go through a filter.

 

[Bperry]

Given I just cleaned out the grids in 48 sqft DE Filter, before I turn on the pump, should I pour 4lb of D.E. slurry directly into the base of the filter body, seal it up and then turn on the pump, instead of pouring it down the skimmer?

I am used to mixing the D.E. to form a slurry and then pour it down the skimmer but this is a heavy green algae pool and I have concerns that I might corrupt the filter if I apply that procedure.

I cannot see a few inches below the top of the pool but I manually skimmed off debris, everything that was floating. There's a Hayward pool robot, it was covered in heavy green algae. I cleaned it using a hose and let it sit in the sun one full day.

Context:

Long time lurker, first time poster. I am nursing my aunt's heavy green algae pool back to health. I'm no pool tech but maintain my own pool. My uncle passed last month and turns out he used to take care of the pool, so no one was caring for it for 2, probably 3 months. When I dropped off my aunt from dialysis I noticed that the pool was heavy green algae. I added 1Gal 10% acid to reduce the pH and poured 4x 1Gal of 10% Cl at the four corners of the pool and used the brush to mix.

To my surprise, the next day, nothing had changed and that indicated the water wasn't turning through the filter.

I took the FNS 48 sqft DE Filter casing apart, washed off all the DE and green algae off it, but now I am lost what to do next - I've never faced this level of contamination before (for my own pool, backwashing is sufficient) so when I restart the DE once a year, my pool water is clean and sanitized unlike this mess

You’ll clog up the filter very fast running thick blurred water through it. The issue is a lack of chlorine, not filtering. Ideally follow the advice above and get the chlorine levels up to normal and recirculate the water if you can.

 

[plnewb]

Welcome to TFP

Thank You! I am excited to finally have a reason to post. You guys are great!

Do you have a Multiposition Valve on the DE filter or just a simple backwash plunger?
If you can put the MPV in recirculate position, then add your chlorine by following SLAM Process

It's not a MPV but a push/pull valve - I can see why it would be called a plunger - which is a more "correct" term to use?

Do you know your CYA level? Run like that for a day or 2.

I do not, I do have questions about the kit here: Why isn't the TF-100 sold on amazon?

However, I learned almost everything I know from my late uncle, who owned and maintained this pool and he hated tablets (due to CYA). He never used CYA and would instead add NaClO atleast once in the evening and sometimes before going to bed when our families were over. I remember him doing that for decades

One idea is to bypass the filter

I am curious what that would achieve - doesn't the dead algae need to be filtered out of the water for the pool to clear up?

This will start the process of killing the algae, then you can manually vacuum to waste if you want to bypass the filter that way or you can just scoop out the dead algae but that only gets so much before you have to go through a filter.

Are you saying that once I add the proper amount of NaClO (and knowing the right amount of CYA is extremely important to deduce that) to the swampy water, I should start seeing the swamp clear out in a matter of hours?

For example: The sun starts to set ~6PST but the light goes out ~8PST.

1. So if I put in the proper amount of NaClO, I should start seeing the pool clear out within that window?
2. This wouldn't happen without the pump on through - yes? The pump has to be providing a flow so that NaClO has a chance to mix with the water evenly?
3. Which is why you propose the bypass because it allows the pump to do its work without messing up the fabric in the cleaned but DE free filter?

You’ll clog up the filter very fast running thick blurred water through it. The issue is a lack of chlorine, not filtering. Ideally follow the advice above and get the chlorine levels up to normal and recirculate the water if you can.

By recirculate you mean just having the pump run? I ask because I don't have a MPV - just a push/pull valve and I clearly remember MPV having a "recirculate" setting (which I don't have because I don't have an MPV)

Thank You both for your time and insight!

 

[Bperry]

Thank You! I am excited to finally have a reason to post. You guys are great!



It's not a MPV but a push/pull valve - I can see why it would be called a plunger - which is a more "correct" term to use?



I do not, I do have questions about the kit here

However, I learned almost everything I know from my late uncle, who owned and maintained this pool and he hated tablets (due to CYA). He never used CYA and would instead add NaClO atleast once in the evening and sometimes before going to bed when our families were over. I remember him doing that for decades



I am curious what that would achieve - doesn't the dead algae need to be filtered out of the water for the pool to clear up?



Are you saying that once I add the proper amount of NaClO (and knowing the right amount of CYA is extremely important to deduce that) to the swampy water, I should start seeing the swap clear out in a matter of hours?

For example: The sun starts to set ~6PST but the light goes out ~8PST.

1. So if I put in the proper amount of NaClO, I should start seeing the pool clear out within that window?
2. This wouldn't happen without the pump on through - yes? The pump has to be providing a flow so that NaClO has a chance to mix with the water evenly?
3. Which is why you propose the bypass because it allows the pump to do its work without messing up the fabric in the cleaned and DE free filter?



By recirculate you mean just having the pump run? I ask because I don't have a MPV - just a push/pull valve and I clearly remember MPV having a "recirculate" setting (which I don't have because I don't have an MPV)

Thank You both for your time and insight!

I think you’re putting too much emphasis on the pump and filter right now. It’s going to take a week or two of adding enough chlorine each day several times a day to raise the level the amount on the SLAM chart. If you can’t run the pump without filtering, you could get a sump pump to recirculate the water and chlorine, or maybe take the filter grids out (I don’t have a DE filter so don’t know details of them).

Once the algae is dead (if there’s any green, it’s not dead) then filtering or vacuuming to waste to get rid of the bodies will help with that job.

 

[plnewb]

1. I am curious if there's a certain threshold where one would decide on drain a certain % of the existing green water and refill in with fresh water (assuming CYA, copper, algaecide levels were low)?
2. Is it a good idea (even if not financially feasible) to drain a certain % of the existing green water and refill in with fresh water if the pool has gone swampy but CYA, copper, algaecide levels were low?

 

[mknauss]

Without high metals, CYA, or calcium hardness, it comes to cost of water and potential for pool shell to pop out of the ground.

 

[HermanTX]

It's not a MPV but a push/pull valve - I can see why it would be called a plunger - which is a more "correct" term to use?

Push/pull is probably more commonly used.

He never used CYA and would instead add NaClO atleast once in the evening and sometimes before going to bed when our families were over. I remember him doing that for decades

I am sure he may have used CYA if this is an outdoor pool as UV would consume the chlorine very quickly without it. But he sounds like a smart man, so my guess he used a little CYA. The recommended amount is a CYA level of 50

Also, he used liquid chlorine, also referred to as bleach. You can purchase it at Walmart and Home Depot and similar stores. It is called Pool Essentials and has a sodium hypochlorite of 10%. sometimes you find other brands with 12.5%

You would need a test kit to test for CYA, pH, FC (free chlorine) - look at
Test Kits Compared
At TFP we believe in 2 critical foundations - test your own pool water and refer to the FC/CYA Levels for proper sanitization.

I am curious what that would achieve - doesn't the dead algae need to be filtered out of the water for the pool to clear up?

Yes - eventually you have to go through the filter to clear up the pool but since you have a DE filter, I was trying to avoid doing that initially while you are in the early stages. Try to clean as much gunk as possible before you go to filter

Are you saying that once I add the proper amount of NaClO (and knowing the right amount of CYA is extremely important to deduce that) to the swampy water, I should start seeing the swap clear out in a matter of hours?

There is no set time table to clear a pool. What is important that the process is followed and you test every 2-4 hours during the day to top up your FC so it is at SLAM level. The better you do this, the quicker it will go. But every pool is different based on size, how bad the algae is, etc. Take a picture now and then take one every day at the same time. Then after day 2 or 3 you can look back to day 1 and see progress.

1. So if I put in the proper amount of NaClO, I should start seeing the pool clear out within that window?
2. This wouldn't happen without the pump on through - yes? The pump has to be providing a flow so that NaClO has a chance to mix with the water evenly?
3. Which is why you propose the bypass because it allows the pump to do its work without messing up the fabric in the cleaned and DE free filter?

Liquid Chlorine plus filtering will clear the pool. Also need to brush and ensure no hidden algae in ladders, or light fixtures, etc. If you have a cover, don't put it on but ensure it is also clean

Your pump needs to be running 24/7 through this process

I think you will need to run the pump with filter. Now you could vacuum to waste (your push/pull valve has a waste setting during back wash) This would mean you get the big stuff off the bottom but you will need to add water. That will affect your levels of CYA and FC so there are pros and cons to vacuuming to waste.

By recirculate you mean just having the pump run? I ask because I don't have a MPV - just a push/pull valve and I clearly remember MPV having a "recirculate" setting (which I don't have because I don't have an MPV)

Thank You both for your time and insight!

Yep - forget that since you have a push/pull backwash valve.

 

[HermanTX]

1. I am curious if there's a certain threshold where one would decide on drain a certain % of the existing green water and refill in with fresh water (assuming CYA, copper, algaecide levels were low)?
2. Is it a good idea (even if not financially feasible) to drain a certain % of the existing green water and refill in with fresh water if the pool has gone swampy but CYA, copper, algaecide levels were low?

You do not state the volume of the pool. If you wish to exchange water, then I would recommend the no drain water exchange. See below for details.
However, if you pursue this, you will need to brush, brush, brush to ensure you are actually removing algae gunk from the pool.
Some people have elected to drain and start fresh, but algae is still there, so you still need to SLAM, it just becomes a little easier.

Draining - Further Reading

www.troublefreepool.com

 

[wireform]

Before you do anything you need your own water analysis via a good kit otherwise you're wasting your energy and chemicals.

 

[plnewb]

going to take a week or two of adding enough chlorine each day several times a day to raise the level the amount on the SLAM chart. If you can’t run the pump without filtering

Here's how I am "bypassing" the DE Filter right now:

I have taken the grids out of the DE Filter and am running the pool pump. The DE Filter currently reads 14psi, so the "base pressure" (is there a proper term for it?) of this system seems to be 14psi

I added 1 gal of 10% HCl and 6 gal of 10% NaClO to the 21000 pool last evening, NO change in the green

Can't wait for the TF-100 to arrive. Should I just keep pouring 1 gal of 10% HCl and 6 gal of 10% NaClO every day? That's ~$40/day

 

[wireform]

No, too many unknowns to throw that much $$. 5ppm FC daily till the kit arrives and then do all the tests in the kit .Then you can make a calculated decision how to approach it.

 

[Bperry]

Here's how I am "bypassing" the DE Filter right now:

I have taken the grids out of the DE Filter and am running the pool pump. The DE Filter currently reads 14psi, so the "base pressure" (is there a proper term for it?) of this system seems to be 14psi

I added 1 gal of 10% HCl and 6 gal of 10% NaClO to the 21000 pool last evening, NO change in the green

Can't wait for the TF-100 to arrive. Should I just keep pouring 1 gal of 10% HCl and 6 gal of 10% NaClO every day? That's ~$40/day

Don’t fly blind. Wait for your kit so you don’t waste money.

 

[plnewb]

5ppm FC daily till the kit arrives and then do all the tests in the kit

OK, going by rough numbers, if I have a 22kGal pool that's all green and I have 10% NaClO that I need to dunk a bit over 1 Gal to maintain 5ppm FC?

Is there a calculator for this? The app?

 

[HermanTX]

OK, going by rough numbers, if I have a 22kGal pool that's all green and I have 10% NaClO that I need to dunk a bit over 1 Gal to maintain 5ppm FC?

Is there a calculator for this? The app?

The
PoolMath app will help you do the calculations.
1 gal LC will increase 4.5ppm of FC. Continue with that daily.

1 gal of MA will drop your pH by 1.4 which will tank it. Do NOT add MA unless you can test for pH. You want to keep pH between 7 and 8.

 

[SoCalPoolFool]

It's actually NaOCI Sodium Hypochlorite

 

[plnewb]

It's actually NaOCI Sodium Hypochlorite

OK

BTW - Do we have a buying group in SoCal where we can buy quantities in bulk and then meet up or mail to each other or similar?

 

[SoCalPoolFool]

Not that I know of. Walmart has pool essentials 10% for just under $6 a gallon which is a pretty good price. Otherwise try to find a pool store with the yellow HASA 12.5% deposit 4 jug crates is the next best option.