Colloidal Clay

Hey guys,

I was wondering if anyone has ever used chemicals to successfully treat colloidal clay in a private well. My house is only seven years old. And it's been a major headache since moving in two years ago. The whole house 30 micron paper filter works well, but I have to change it about every four weeks. Just wondering what other options exist. Thanks a lot!

Scott in NC

What size filter, and how many, are you using?

You can get 3 to 4 times the change interval, and 1.5 to 2 times the water production per cartridge, if you double the surface area of the filter system.

Colloidal material us usually removed by using coagulating chemicals and granular filters with multiple gradations of aggregate.

Swimming pool filters chemicals are used with sand filters to produce very clear water but you don't want to operate that kind of a system for your well-water system.

If you need to remove the colloidal clay and your 30 micron filter is providing adequate clarity then your best solution is to increase the number of cartridges in parallel and shop for the best price on cartridges.

Pretty good advice if it ain't broke don't fix it but you can make it bigger/ better.

My experience is more towards the municipal sized end and I'm surprised that a filter works as well as he described.

I have one of the larger GE SmartWater brands installed. I have been considering installing more in parallel.

The 30 micron isn't 100% effective. Some still passes through. Just not enough to cause noticable laundry stains.

I had a smaller micron carbon that only lasted a week. The filter was so clogged I could literally peel the clay off with a putty knife. I also suspect iron bacteria, as the typical black slime can be seen floating in my toilet.

Thanks for the previous input

If you need a little better filtration you can get finer pleated cartridges. Some down to 5 microns are washable. Finer cartridges, with increased number of units in parallel, would give you better removal and satisfactory life.

Filter life will always depend on the amount of material to be removed and it is best to remove as much as possible ahead of more expensive cartridges such as carbon.

I use cotton string wound cartridges with very low flow rates (about 2 GPM per 40" long cartridge) which give good life and fine particle removal because they are collecting material in depth. They are not washable.

I think that a large fraction of the material you are removing is much larger than colloidal.

There is a good description of various filtration systems at the link below.
http://www.nesc.wvu.edu/pdf/DW/publications/ontap/tech_brief/TB3_Filtration.pdf

One of the systems often used in households is a backwashable sand filter. That is most like the system described as "Direct filtration" in the descriptions at the link. Part of the description of direct filtration includes the statement:

Thanks! I'll check out the web site.

The filter I'm currently using is the pleated/fluted type.

Scott

I am a Certified Water Specialist III, 15 years in water treatment.
Colloidal material clays or otherwise are particles that are so small they don't settle out of suspension. I see these discussions of 30 microns, 5 microns, etc. That is way too big. Colloidal clay particles are generally in the submicron size, i.e. below one micron. Some of you say you have a 30 micron filter and it is getting some of it. That is incorrect. It may be getting the suspended clay solids, but the colloidal material is passing right through it.
We have submicron filters that can be used in whole house applications with double oring seals specifically for this purpose
http://www.bigbrandwater.com/waterfilter6.html

Regards
Dan Saltsburg
Big Brand Water Filter, Inc.
21947 Plummer Street
Chatsworth, CA 91311
www.bigbrandwater.com

You should take a look at the GE ultra filtration systems. They are the Zenon systems and a different one (is not certified for removing bacteria/virus) that may be cheaper with similar or same filtration. I have not looked at the new ones.

The Zenons automatically wash the filters at night. Expensive, but essentially user involvement free.

HI Scott, I'm hope by now you've fixed your clay problem, but I'll reply for others reading this thread. Colloidal clay is problematic because its a sub micron contamination meaning that regular filters won't work. The chemical treatment works by coagulating the particles and clumping them into pieces that can be mechanically filtered. Unfortunately, a standard dirt and sediment filter with 30 micron filter will continue to clog. We suggest and sell a multi-media filter with a backwashing valve to rid the water of the coagulated particles. Instead of replacing filters, the unit cleans itself on a timer you set. The last and often forgotten component of this system in a retention tank. The injected coagulant needs sufficient contact time to work. A fully working and complete unit consists of 1. A chemical feed pump, 2. A solution tank to store the coagulant, 3. a retention tank for contact time, 4. a multi-media filter to remove particles. The task gets slightly more complex because there will be a small amount of trial and error to arrive at the right dosage. And finally, there is a new filtration system called "nano filtration" or "ultrafiltration" which takes our sub-micron particles. We've used a handful of these and each has worked very well with one exception for extremely high contamination. The advantage is that there are no chemicals but the unit costs more. Good luck and I hope this helps. Kyle Chapman www.homewatersystemsonline.com 845-255-4475
If you think you have colloidal clay but aren't sure, I posted a video of some samples from the field. http://www.youtube.com/watch?v=lD5dL0wp3zQ

[video=youtube;lD5dL0wp3zQ]http://www.youtube.com/watch?v=lD5dL0wp3zQ[/video]

I've been living with this clay issue for over a decade now and have gotten to the point that it is acceptable; there continues to be clay but maybe less than 5% of what we used to have. Just like homewater systems said, to do it right, you really do need a holding tank. My system cost me $3K about six years ago and is still only acceptable. I had so much clay I changed filters weekly, 5 microns...the Big Blue filters which were not cheap, and that only removed the chunks of clay, not the colloidal bits. My toilet tanks had a couple of inches of clay settled in the bottom and who knows how much is in my pipes. After testing the water, no bacteria, just the clay. By the way, the color of the clay is gray.

My filter tank back flushes three times a week and the medium needs to be replaced every 7 years or so at $600 per filter. I use pool coagulant, best bang for the buck, rather than the aluminum SOP. Because of my area, country with a lot of wells, our town has a place to get water for free, one gallon at a time, so I bought a water dispensing system that holds the 5 gallon tanks. I fill those up and use that water for drinking and cooking while the filter system takes care of the household water. That water is drinkable but we chose not to, more for psychological reasons rather than rationale reasons!

The other option is to simply pay for water to be shipped in but that's expensive mainly due to the price of fuel plus, initially, you'll have to buy a large holding tank and place in a basement or dug relative deeply in the ground. Or you could try digging another well for another $3K. In my opinion, the most cost effective way to have acceptable water is to purchase the filtration/back wash system with as large a holding tank as you can afford, around $3-4K and spend $20-$30 per month for the coagulant and bleach, and then decide if you want to purchase drinking water. Out of all the issues that can happen to well water, colloidal clay is probably the toughest to take care of and requires action on the part of the owner every couple of weeks to monitor the filtration system.

A word to the wise. If you ask someone to put in a system for you and they say it's "easy" to take care of or they don't know what colloidal clay is, don't let them touch your pipes. If they apologize, tell you it's expensive and say they can reduce the problem significantly, meaning they probably can't guarantee eliminating the problem, then they're being honest and it's probably worth going with them. I will say this, while my problem has not been eliminated, it was well worth the money because it is now a minor annoyance rather than a major headache.

I would suggest getting a lab to determine the size of your particles. Also how much there is per some test volume. Then you will know where to target your filter.

The filters I mentioned above in post 8 can be you solution. If the filtration particle size is a good match, talk to a dealer about the volume of clay passing through. If it is too high it may clog the filter. The filter regenerates daily to clean the membrane. There are several levels of the backwash to deal with more or less gunk. I don't remember off hand, but the filter is down in the nano range. And that was 10 years ago. They will take out everything down to viruses. If there is just too much to handle, you might still have to use a settling tank. But maybe without the mess of coagulants. Maybe a sand prefilter.