Problem with Sand-Based Pool Filter

Had the same problem, the rubber seal in the valve housing on top of the filter gets worn, and the water passes across the seal, not passing through the sand, which has greater resistance?

The whole valve was just replaced a couple of months ago because of leakage to the waste port with loss of water.

Hi,

Did you thoroughly rinse the sand before replacing?

I think that 4 years is about the life span of filter sand.

There are additiives which one can add which bind the fine sediment and stop it from being released into the pool, speak to your pool guy.

If this is not an option remove all automatic pool cleaners and allow the pool to filter for a day or two. The sediment should collect at the bottom. Take a manual vacuum and vacuum out the sediment with the pool pump selector set to waste. This will take the sediment directly out of the pool and not through the filter. There is a tendency to try go to quickly in order not to waste too much water. Don't fall into this trap, all you will do is to stir up the sediment. Make sure your pool is full before starting, you would not want to drop below the wier halfway through.

Andrew

They don't change the sand at the beach for good reason, it lasts a lifetime.

The beach replenishes its self as the grains of sand get broken down and you no longer see the silt.

Use a product such as omni-clear. It binds the fine particles into larger clumps to filter out. Follow directions on bottle as using too much acts as a dispersant.

Yes I believe these are called anti-floccukants such as Joli Jellie and pool clear,both will bind the fine particles and get rid of the cloudy stuff.Good Luck.

actually those would be flocculants, not anti-flocculants, and the large sturctures formed are flocs.

Take one or two layers of polyester velvet fabric used for automobile seat covers, pass turbid water from the raised velvette top face and check the clarity of filtered water.

If you find the effective performance, improvise a velvette cloth filter suitability to your end use including back wash provisions. A simplest , viable low cost long time workable water turbidity removal filter.

Try and report feed back.

Regards

I'll try this when I can get some of the fabric. Thanks. This sounds like a good solution if I am able to rig up such a cloth filter.

These fabrics are available plenty in furnishing, upholstery or floor mat whole sale shops. Enquire and search. I am sure you can get it without much difficulty. Best wishes.

Perhaps you should actually replace the sand. Make sure you use sand that is specified for use in pool filters and not just any sand.

The sand had just been replaced with sand specified for use with pool filters.

Got a Pollen problem it sounds like and a Paper Filter is needed

pollen is carried by the wind your fighting a losing battle without a paper or fiber filter to hold the pollen for removal .

I'm pretty sure this stuff is not pollen. The months of heavy pollen in this area (east central NC) are April and May.

My hot tub is near some tree and even now in Tennessse pollen falls off the leaves. Yellow globs in the bottom of the hot tub if I don't run it daily.

Thanks. I was actually considering adding some diatomaceous earth to the sand filter through the strainer to improve filtration efficiency, but this process might wind up ruining the sand filter according to some internet sources.

Thanks. Sounds like a nice simple fix! Will try it.

Actually flow rate is not directly related to void space, as clay has a fairly high void space. Flow rate is related to porosity, which is the continuous macropores that make up a portion of the void space, in finer particled materials many of the pores are not continuous.

You are correct, I mis-typed. Thank you for catching my error. Lord knows somebody needs to keep an eye on me.

Well, I am not clear also, I should have stated that it is related but not directly related to porosity. It is related to the continuous pore space, but there is discontinuous pore space, which increases as the materials get finer grained. Also, there are the size of the pores that plays a major factor on the rate at which water flows, as many smaller pores of same cross-sectional area will not conduct water as fast as few large pores due to surface friction with the pore walls. There are, however, numerous equated relationships for a variety of soil materials over a variety of limited gradations ranges that relate porosity to conductivity of the material. Of course these are experimentally based, and many occupy same gradation ranges and will provide significantly different results usually within 1 or 2 order of magnitude of each other.

Were you careful when dumping the rock and sand in and not cracking or breaking a finger off? Also give it a good backwash as you could have channeling.

Yes, I was very careful about that.

Do you only check the chlorine and pH levels? My water was cloudy earlier this year. My alkalinity was low. I believe I eventually added 15-20 lbs of sodium bicarbonate to get the alkalinity to a good level. The pool has remained clear since then.

I have also had problems with the filter causing the pool to be cloudy. I replaced my filter 3 years ago (my old filter was 20 years old). My pump started working better and my water was clearer. I generally replace the sand every couple years (above ground pool) because it gets clogged with dead skin cells, oil, ... The sand doesn't cost that much and it's not worth the hassle and cost of using chemical cleaners, etc. to improve the efficiency.

Because of the acidic nature of the rainfall here, I use a lot of bicarbonate and carbonate to maintain a pH above 7.5 and so alkalinity is not likely to be an issue.

Add in a sediment filter on the high pressure side for a few days! and 1/4 cup muractic acid

Seems to be a problem with clay or other fine particles

Alum is a good flocculant and is cheap.

Epsom salts can also be used but has quite an effect on anyone who happens to drink the water while swimming!

When travelling out back, many people carry a small amount of alum to clarify water from clay lined dams.

Thanks, Sceptic..

I agree with your assessment that the problem is fine particles. As for Alum (aluminum sulfate) or Epsom salt (magnesium sulfate) being good flocculants and cheap as well, I also agree. Ferri-Flocc (ferrous sulfate / ferrous aluminum sulfate) and gypsum (calcium sulfate dihydrate) are to other ones.

However, as I posted earlier, any flocculant is only effective when it has the correct charge, is the correct type; i.e. anionic, cationic or non-ionic and in many cases has the correct molecular weight.

Normal pool flocculants and clarifiers did not work for me on my pool problem and I do not believe they will be effective in this case (based on my experience at home and at work).

The ones you mention will affect the pH of the pool and could cause other problems including forming additional particulates in the pool. Pool flocculants and clarifiers are specifically selected or created so as to not cause additional problems. They work best on dirt, dust, pollen and other airborne pollutants that get into pools. In my case (and I believe this one) my problem was not any of these.

Some general information can be found at: http://www.flocculants.info/ , also at the websites of GE Betz, Allied Colloids, Ciba, Cytec and others.