Backwash filter (calcite) question...

[CindyBlue]

First off, let me say that I know very little about water treatment systems.

We installed a new water treatment system in January, replacing an old one that my dad had let go so it didn't work anymore. It has a water softener and a calcite backwash filter.

Our water is horrible - very rusty, a deep orange. The new calcite backwash filter is set to backwash every 2 days, and it pushes a LOT of water through. I can't remember how much, but I think it was at least 40-50 gallons or more. That water just goes out through a pipe to the pasture where it soaks into the ground. I'm told it's too saline to use for plants or anything else useful.

Since the new water treatment system was put in, our water is wonderful - very clear and doesn't stain the clothing in the washer orange anymore!

Right now, there's a very bad drought here. We were wondering if we could set the backwash filter to backwash over a longer period of time without damaging the system, in order to save water from our well. We have just gotten off the phone with the company that put it in, and they taught us (over the phone, thank goodness!) how to change the number of days in between backwash flushes. We just set it to three days instead of the two they set it at when they installed the system.

But we forgot to ask them if doing so will damage the backwash filter by leaving too much of the "bad stuff" in our water in the tank to be washed out if it's not backwashed often enough.

We have an appointment for them to come out on Friday, but that will cost $200+ just for advice. I was going to call them again before that to ask about the possible damage issue by increasing the number of days between backwashes. But I thought I'd ask here to see if anyone knows anything about this!

 

[ERD50]

The new calcite backwash filter is set to backwash every 2 days,

I'm a little surprised that a new system doesn't run "on demand" rather than the old-style "set number of days" timer.

The on demand type monitor how much water is used, and will back flush overnight only when it estimates that it is needed.

Other than that, all I know is that this type is for treating the acidity in water (I'm more familiar with the ion exchange water softeners for hardness). If no one comes along with experience (although I think any advice is going to be specific to your water profile and usage anyhow), you should be able to educate yourself from the internet before you meet with the installer, so you know what to ask, and how to process any information they provide.

-ERD50

 

[Mark1]

I'm no expert (in fact I wasn't even aware of calcite filters until this post), but I was curious so I did a quick search.

Based on this vendors website (https://appliedmembranes.com/calcite-neutralization-filters-neutralize-acidic-or-low-ph-waters.html) and this quote within (.....Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates....), it appears that backwashing is to maintain good solid-liquid contacting within the calcite bed. Without good contacting and mass transfer, none of these bed treatment processes will work. For example, over time the water may start to form channels through the bed and no longer come in contact with the calcite solids. The backwashing may simply fluff up the solids inside so that the calcite solids can resettle in a tightly packed bed again and eliminate this channeling effect.

Hopefully someone will reply and say my theory is wrong and I can learn something.

 

[CindyBlue]

I'm a little surprised that a new system doesn't run "on demand" rather than the old-style "set number of days" timer.

The on demand type monitor how much water is used, and will back flush overnight only when it estimates that it is needed.

Other than that, all I know is that this type is for treating the acidity in water (I'm more familiar with the ion exchange water softeners for hardness). If no one comes along with experience (although I think any advice is going to be specific to your water profile and usage anyhow), you should be able to educate yourself from the internet before you meet with the installer, so you know what to ask, and how to process any information they provide.

-ERD50

Thank you.

I've done a fair amount of internet research on the subject that past couple of days, but can't figure out what determines the need to backflush, and how bad our water is that would make it more necessary to backflush every two days, as it was set when installed... Or could we make it every four days or more to save water - but would it then still work with our bad water.

We know that one is "on demand" - and we think it's the water softener part, not the backflushing filter part. It was not explained to us when it was installed, and I didn't know enough to ask any questions. If it weren't for the drought, I'd not even need to ask...sigh...

I guess we need to have them come out again.

 

[CindyBlue]

I'm no expert (in fact I wasn't even aware of calcite filters until this post), but I was curious so I did a quick search.

Based on this vendors website (https://appliedmembranes.com/calcite-neutralization-filters-neutralize-acidic-or-low-ph-waters.html) and this quote within (.....Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates....), it appears that backwashing is to maintain good solid-liquid contacting within the calcite bed. Without good contacting and mass transfer, none of these bed treatment processes will work. For example, over time the water may start to form channels through the bed and no longer come in contact with the calcite solids. The backwashing may simply fluff up the solids inside so that the calcite solids can resettle in a tightly packed bed again and eliminate this channeling effect.

Hopefully someone will reply and say my theory is wrong and I can learn something.

Thank you - this makes a lot of sense.

Now...how often does the backwashing need to occur? Does the number of days between backwashing depend on the quality (or lack of quality, in our case!) of the water passing through the calcite tank? If so, we will probably be stuck with wasting all that water because we'll have to keep it set to backwash every two days. If not, maybe we can make it four or five days in between backflushings...

 

[latexman]

This website says “ every 3-7 days: 10-16 min per backwash “ for well applications.

Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates. Looks like every 3 days is safe.

You could let it go until you see a flow rate decrease (packing), then decrease it 1 or 2 days. I recommend you develop a simple flow rate test ( time to fill a 1 gallon container? ) and keep a log. You should quickly become an expert!

 

[CindyBlue]

This website says “ every 3-7 days: 10-16 min per backwash “ for well applications.

Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates. Looks like every 3 days is safe.

You could let it go until you see a flow rate decrease (packing), then decrease it 1 or 2 days. I recommend you develop a simple flow rate test ( time to fill a 1 gallon container? ) and keep a log. You should quickly become an expert!

This is great - so informative! I can hardly wait to show it to my hubby!
Thank you!