How to filter algae out?

[threekittens]

I was sooooo stupid, lazy or whatever and neglected putting chlorine in my pool a few weeks ago. So when I finally checked it last weekend of course the bottom was covered with algae. I used the brush and swept the bottom best I could. Of course it became extremely green t/o when I did that.

Over the past week I've tried to keep the chlorine level up but that was it.

Today I'm trying to vacuum the bottom and all was go well till I noticed the water returning back into the pool is green. I was about 2/3 done with vacuuming. I then turned the filter to rinse till the glass thing was clear. Then back to filter. What then returned into the pool was even greener.

Does this indicate something wrong with the filter? We had a bad accident early this summer where we had the filter on overnight with it CLOSED and of course blew out a tubing and later the filter tank developed a pin hole sized tank. We swapped the filter out for a used set we bought. All had seemed fine the rest of the summer.

[threekittens]

Hopefully I just figured out what I was doing wrong. Helps to take a look at the filter manual. :-/

I was only doing a rinse and then waste before. I think.

I've now newly acquainted myself with the "Backwash" setting. Just did that it horrible dark green stuff came out for quite a while. I followed that with a rinse, more green water, and then eventually back to filter.

Didn't see the obvious green going back into the pool this time. Of course I have the whole thing so stirred up by now all the water is green. Dumped some more bleach it and gonna let it be till tomorrow. Hopefully the vacuuming goes better then.

Or should I just keep brushing it every day and let the filter do the work?

This was 4th summer with the pool and 1st algae problem of any type. Guess I got too comfortable with my relaxed pool maintanence style.

[waste]

I thought I had posted this here before, but if I can't find it - you probably can't either ( I wrote this last spring for the DE filter owners)
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Use and Care For most DE Filters:

(The units I have a lot of experience with are made by Hayward – so most of this applies specifically to them, but the principals apply to all DE filters)

1) Basics –

A DE filter is one which uses diatomaceous earth (~ skeletons or fossils of prehistoric one celled plants) to remove all but the finest material from the water. The DE is a white powder which is mined in various places around the world which was formed by the evaporation of the water that these critters lived in. The DE is kept in the water flow of the filter because it coats the internal grids or fingers which make up the filters internal ‘nest’ allowing dirt and debris to be captured by the microscopic paths created by the coating. Because of the nature of the ‘paths’ through the DE coating, algae – which is the approximate size of the paths – can easily and quickly congest a DE filter, most DE filter owners find this to be the biggest drawback of owning one. The DE must be added to the filter via the skimmer, with the pump running, the amount to add is dependent upon the size of the filter. When adding DE to a filter, most manufacturers recommend mixing the powder with water before pouring it into the skimmer – I have found that adding the powder directly into the skimmer is equally effective, if you have more than 1 suction source operating at the time of addition. (having a second, or third, suction source allows the DE rich water from the skimmer to properly mix with ‘non- DE water’ from the other source(s) to evenly coat the grids).

However, DE filters, while providing the finest filtration, DO have their downsides! If you do a ‘backwash’ (discussed later) or do a thorough cleaning of the filter, you need to add more DE to it – and, if you add too much or too little, you’ll likely have filter problems! Too much DE will clog the filter and decrease the efficiency of it. Similarly, too little DE will not catch enough ‘dirt, etc” and cause the grids to clog up with the debris, both of which require a manual cleaning of the grids and possibly a chemical cleaning of them. Also, ‘bleeding’ the air out of the unit before adding DE is KEY! – the fresh DE can only coat the parts of the grids that are in water!

Knowing how much DE you are actually adding to the unit is VERY important! The best way is with a premeasured scoop – they are inexpensive and well worth the $ spent, any place that sells DE should have one available. DO NOT USE a 1lb. scoop or canister that is not specifically for DE (ie. A 1 lb. coffee can only holds ~ ½ lb. DE) If you have an accurate scale that will allow you to weigh the container first and then the weight of the DE when it’s full, that’s fine -- just be SURE to know ~ how much DE you add when you are adding it!

2) Types –

There are 2 different types of DE filters:
The first uses ‘fingers’ (fabric wrapped hollow tubes, usually 100/ filter) to collect a layer of the DE on. This style is also known as a ‘bump’ filter because the DE can be ‘recharged’ via the use of a handle which moves the whole assembly up and down to expose new pathways in the DE coating without having to replace any DE (I’ll talk about ‘bumping” a filter in a minute.) (There are some ‘grid’ filters which have a handle on the top connected to a plastic plate which operate the same way)

The newer models have a series of grids to collect the DE and either have a multiport valve or a ‘push/ pull’ valve (of which I will speak very little). These units allow you to ‘backwash’ most of the DE out when the filter needs to be cleaned. (* some localities do not allow wasted DE to be flushed into sewers or even onto your own property – in that case a ‘separator’ would need to be installed on the backwash line).

3) Start - Up

The fabric which holds the DE does very little to filter the water! As such, a DE filter needs to have a coating of DE on the grids/ fingers as soon as the pool is started up. Your installer or pool tech should do this for you the first time and give you a complete lesson on operating your pool (called ‘pool school’- it’s a lot of info all at once and it is very understandable that some of the info is forgotten by a pool owner). The amount of DE required by each filter is determined by the size of the filter – there should be a label on the filter identifying the size of the unit and how much DE it requires when completely clean. As said, KNOWING how much DE you are adding is key! Make sure to note what the pressure gauge reads when the unit is clean and freshly coated with the DE!!

4) Maintenance

Your filter should run anywhere from 8 psi to 20 psi with fresh DE put in it, depending on your pool and filter system. When the psi rises 8, it’s time to clean the used DE out of it. (when doing any filter work, turn off the pump!)

Bump filters:
1) open the air valve on the top of the unit for ~ 5 sec. and close (bumping with the unit full of water will harm the unit!)
2) Slowly push the handle down and quickly raise it up 4 – 6 times.
3) Now turn the pump back on and see if the psi went down, if it didn’t drop more than 2 psi, you need to dump the used DE.
4) (if you need to dump the DE) – Open the drain outlet on the filter after doing steps 1 and 2 and run the pump for 20 seconds. Close the outlet and run the pump for a minute (don’t do this if you have an algae problem! The uncoated parts of the fingers will collect algae too quickly and clog), then repeat the procedure (make sure you open the air relief while the pump is running until water comes out of it)
5) At this point, you have removed ~ 80% of the old/ used DE so only add 80% of the DE you would use in a new or fully clean filter!!

Grid filters:
1) Pretty much the same as bump, except you have a multiport which allows you to backwash the filter when the pressure rises 8 psi.
2) (always!! Turn off the pump when changing multiport positions!!) Turn the multiport to ‘backwash’ and restart the pump, watch the view-glass or the end of the discharge hose to see when the backwashed water becomes ~ clear. When it is fairly clear, turn the multi to ‘rinse’ for 15 – 20 seconds and then back to ‘backwash’ until the water runs ~ clear again. Repeat the ‘rinse/ backwash’ until the water comes out clear when backwashing, add a short ‘rinse’ and the filter is about as clean as you’ll get it using the ‘backwash’ function.
3) If the water in the pool is fairly clear, I’ll throw in a 1 min filter cycle and do the ‘backwash/ rinse’ cycle(s) again.
4) At this point, you have removed ~ 80% of the old/ used DE so only add 80% of the DE you would use in a new or fully clean filter!!

When bumping/ backwashing doesn’t work:

Sometimes just ‘dumping’ the old De isn’t enough to get you back to proper filter performance – this can be caused by algae (or some other fine debris clogging the DE), or neglect (you didn’t clean the filter soon enough), or the grids/ fingers getting clogged up.

At this point, you need to take the filter apart and manually hose them off (it’s a wet process – so be prepared to get ~ soaked). I recommend the manual hosing every year (I like doing it in the fall when the pool is being closed because, then you know the filter is ready for another season)

If , when manually rinsing the grids, you notice that water is staying in the membrane for more than ~30 seconds, it’s time for a chemical cleaning!

To chemically clean the grids/ nest:
1) Have a bucket/ container large enough to hold the entire assembly
2) #1 Add some TSP (tri-sodium-phosphate) to the water or some electric dishwasher detergent to the water and soak the grids for 3 hours – this will ‘de-grease’ the membranes and is the first step in cleaning them, rinse with hose and get ready for step 3.
3) Dump the container, refill with water and add muriatic acid to the water so that you have a 10:1 water: acid mixture and soak the grids for another 3 hours, this will clean any calcium off of the grids. Rinse grids again and reinstall them in the filter.
4) Now, run pump and bleed off the air from the filter and add 100% of the DE the filter calls for.


I Hope that this is enough for most DE filter owners; if you have any questions, I’ll be here to answer them
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I hope this will help you properly care for your filter in the future

Good luck with the algae and, may it never be a problem again!!

[waterbear]

Trying to filter out live algae is like trying to collect sand in a sieve. It just doen't work! Kill the algae first with chlorine and then filter out the dead algae!

[aylad]

How high are you taking your chlorine level, and what is your CYA level? You've got to get the chlorine up high enough, and stay there for long enough, to kill the algae before you're going to be able to get it out of your pool.

Janet

[threekittens]

I just got some numbers.
CYA is approx. 70
Ph 7.8 or so
Chlorine 18-19 (I had dumped in 2 Dollar General jugs of bleach today)

I've never seen the Ph that high. I've never had to add acid. Just Borax.

I see that I do have an older jug of "dry acid" out there that I bought when I had my easy set pool for a couple of years before this above ground. Never used it. Just bought a Ph Up and Ph Down at that time thinking I'd need them.

Should I put some of the dry acid in or just wait till I get this cleaned up?

Its past swim season here (Iowa) so just needing to get it cleared up before closure which I'll probably wait to do till the end of the month when temps are consistently lower.

Of course I've also got leaves constantly falling in. Had to shut the filter off last night as I knew the skimmer would be getting plugged up with too many leaves if left unattended that long.

I can see the bottom of the pool but its really cloudy and generally green. The water looks fairly clear though when I take a sample to test.

The really bad news is I'm almost out of R-871 titration stuff.
I'll order some in the AM. Until that gets here I'm going to had to use some of the simpler (and old) kits I've got.

[aylad]

Keep in mind that high chlorine levels will give falsely high pH results, so I would not adjust your pH unless your Cl is lower than 10. That being said, with a CYA of 70, you need to bump your Cl up to 20-25 in order to kill the algae. You need to keep it there by testing and adding more to get back up to that level, 2-3 times daily if possible--the more consistent you are about keeping the Cl up, the quicker the green will clear.

Janet

[Watermom]

And, to add to what Janet said, run your pump 24/7 while you are trying to clear your water.