Iron filter line reduction

[ccroasmun]

Thanks in advance of any help. I am installing a Katalox-Light back wash filter and the best deal I have come across is actually a commercial valve with 1" supply. I have 3/4 here at the house and the vendor said they would include reduction fittings but unsure about the 3/4 suppluy feeding a 1" valve.

Specs on this filter are:
- 10 GPM Max
- 8 GPM Normal
- 7 GPM Backwash
- 12" x 52"
- 2 cubic ft Katalox light
- Gravel bed, not Vortec

My GPM is at 8GPM, and this unit is less and seems to exceed normal flow rates of residential units I've seen and is a bit cheeper.

What my concerns are is back washing and maintaining normal flow. Most residential which fall into my specs are 1.5 of media 10x54 with normal flow rates around 6 GPM.

I like the idea of the greater volume of media, I think a vortec distribution would be better, but biggest concern is the 3/4" supply feeding this unit and especially without vortec tube if the greater volume of media and the reduction may not be enough for proper backwashing.

In a nut shell:
- Will the 3/4" feeding this 1" valve have a negative effect?
- Since I'm pushing the limits with my 8GPM of incoming volume, with the specs on this thing, may the gravel bed design make this unit marginal for me.

Thanks again in advance,
Chuck

 

[Reach4]

My GPM is at 8GPM

Where did you get that number?

 

[Sponsor]

 

[ccroasmun]

Where did you get that number?

I calculated it

 

[Reach4]

I calculated it

That is unusual. What did you factor into your calculation?

 

[ccroasmun]

That is unusual. What did you factor into your calculation?

Gallons pumped until pumped kicked on and seconds until pump kicked on. As I recall, I'll have to double check the procedure I found on the net, but found several suggesting same procedure before I did it.

 

[ccroasmun]

Are you thinking 8GPM is low, or high for residential?

 

[Reach4]

8 GPM would be well within a common range for a typical house.

So there are various ways to measure the flow. Your way makes some sense, but it has some flaws. The amount of water it takes to fill the pressure tank to cutoff can vary with the precharge and the water pressure settings.

Suppose your drawdown number is exactly right for sake of argument. Is your calculation right in that case? No, because centrifugal pumps deliver more volume against lower pressure and less against higher pressure. Your method would be pessimistic. For purpose of backwashing your filter, it does not matter how much the pump can pump against 50 or 60 PSI. Look at the minimum pressure specs, which will be 30 PSI or less. So you care how much the system could deliver to your filter at 30 PSI or maybe even 25 PSI.

On the other hand, the pressure tank will often hold less new water than the drawdown spec of the tank. For one think, the tank will usually have some water still in it as the pump starts. There is an intentional reserve to give a little margin. Plus your precharge may not be exactly optimum.

Knowing the pump and the vertical distance to the well water surface would probably give a better number.

I am not a pro.

 

[ccroasmun]

8 GPM would be well within a common range for a typical house.

So there are various ways to measure the flow. Your way makes some sense, but it has some flaws. The amount of water it takes to fill the pressure tank to cutoff can vary with the precharge and the water pressure settings.

Suppose your drawdown number is exactly right for sake of argument. Is your calculation right in that case? No, because centrifugal pumps deliver more volume against lower pressure and less against higher pressure. Your method would be pessimistic. For purpose of backwashing your filter, it does not matter how much the pump can pump against 50 or 60 PSI. Look at the minimum pressure specs, which will be 30 PSI or less. So you care how much the system could deliver to your filter at 30 PSI or maybe even 25 PSI.

On the other hand, the pressure tank will often hold less new water than the drawdown spec of the tank. For one think, the tank will usually have some water still in it as the pump starts. There is an intentional reserve to give a little margin. Plus your precharge may not be exactly optimum.

Knowing the pump and the vertical distance to the well water surface would probably give a better number.

I am not a pro.

A different calculation method would be great, not sure if calculating it while pump is running may be a benefit when concerning my pumps ability to backwash the filter. As far as a specific flow I am hoping that these DIY calculations and sizing the filter with some overhead would be sufficient.

Beyond whether my calculations are correct, my specific concern is the effect of feeding this 1" valve from the 3/4" supply at this GPM and whether GPM when reducing like this is apples to apples. GPM should still be there, but I am concerned pressure drop may occur and if so is this an issue.

Then whether the traditional gravel bed at these numbers would also be sufficient, or whether a vortec distribution tube would ensure enough overhead to ensure this filter bashwashes sufficiently.

As stated most residential models spec out for my flow at 10x54 tanks with 1.5 cuft of Katalox, this one is 12x52 with 2 cuft and a gravel bed instead of the vortec tube which most the residential models have.

 

[Reach4]

A different calculation method would be great, not sure if calculating it while pump is running may be a benefit when concerning my pumps ability to backwash the filter. As far as a specific flow I am hoping that these DIY calculations and sizing the filter with some overhead would be sufficient.

When the pump is not running, it is the pressure tank providing the water.

Maybe you could get your well and pump data from your well company.

You might also try simultaneously filling 2 5-gallon buckets from your outside spigots. Turn on both spigots fully, and ensure that the pump runs continuously without the pressure dropping. Make sure the pressure stays at least as high as the minimum that the filter requires. For each spigot, throw the empty bucket under the water stream. Time how long it takes to fill each bucket. Calculate. The GPM available would be the sum of the 2 GPMs.

 

[ccroasmun]

Anyone,

Still looking for a reply to my questions:
- Will the 3/4" inch line adapting to 1" for the commercial valve hjave an adverse effect?
- Since I am at 8 GPM and this filter requires 7 GPM is this marginal with the gravel bed and adapter? Asking this due to most residentials seem to be 10x54 to keep backwash under 8GPM. I like this filter due to the extra media and backwash being within my volume, but it is gravel instead of a vortec design.

Thanks everyone!!

 

[ditttohead]

Anyone,

Still looking for a reply to my questions:
- Will the 3/4" inch line adapting to 1" for the commercial valve hjave an adverse effect? No
- Since I am at 8 GPM and this filter requires 7 GPM is this marginal with the gravel bed and adapter? Asking this due to most residentials seem to be 10x54 to keep backwash under 8GPM. I like this filter due to the extra media and backwash being within my volume, but it is gravel instead of a vortec design. Gravel vs vortech... don't worry, I would be more concerned about your water temperature. What is your water temperature? This has a huge affect on the systems backwash rate requirements. What control valve?

Thanks everyone!!

 

[Reach4]

1. No.
2. 7 GPM backwash for a 12 inch tank of KL is on the low side. That is 8.9 GPM/sqft. That would be give fairly low bed expansion during backwash if your water is not so cool. Note the "Backwash Velocity [m/h] vs. Bed Expansion [%]" chart.

You will have a 30 inch media height. The brochure says Min. Bed Depth
29.5 inches, Optimal Bed. Depth 47 inches

 

[ccroasmun]

That was a worry, and I have not followed up on it, thanks for bringing it up. My concern was due to my having everything in the garage. I live in mid-ohio so we have some cold weather definitely. The garage is heated, and this is where my Kinetico Model 60 has been for years but I do not keep the heat on except when it gets into single digits, and even then not all the time. The garage temp typically does not go below 40/42 without heat, in single digits outside I have seen it drop to 38.

I have not check temp yet, what range am I looking for?

 

[ccroasmun]

I'll have to check on the temp, the digital home thermometer I have won't go below 90 somethin. Here's a link to the unit, unsure of the valve it a US Water branded unit. Not sure if I replied correctly last time, did you see my comments?

http://www.uswatersystems.com/us-water-backwashing-katalox-light-filter-1-inch-8-20-gpm.html

 

[ccroasmun]

1. No.
2. 7 GPM backwash for a 12 inch tank of KL is on the low side. That is 8.9 GPM/sqft. That would be give fairly low bed expansion during backwash if your water is not so cool. Note the "Backwash Velocity [m/h] vs. Bed Expansion [%]" chart.

You will have a 30 inch media height. The brochure says Min. Bed Depth
29.5 inches, Optimal Bed. Depth 47 inches

Will have to check the chart, maybe that's why I am seeing the residential units usually being 10" tanks and less cubic foot of media. Most of them are 1.5, some are even 1 cuft to stay within my back wash specs.

 

[ccroasmun]

I see the backwash velocity vs bed expansion chart in the brochure, not sure how to calculate backwash velocity it say m/h, what is m and h. Also what % of bed expansion is needed. Thanks a lot for cutting to the chase.

I checked out your website, but I see you have chosen not to list product specific pages. Shipping cost may be an issue with you being in Cali but what do you suggest from your product line.

 

[ccroasmun]

1. No.
2. 7 GPM backwash for a 12 inch tank of KL is on the low side. That is 8.9 GPM/sqft. That would be give fairly low bed expansion during backwash if your water is not so cool. Note the "Backwash Velocity [m/h] vs. Bed Expansion [%]" chart.

You will have a 30 inch media height. The brochure says Min. Bed Depth
29.5 inches, Optimal Bed. Depth 47 inches

I ran GPM again a second way, the formula I used this time was 300 / "# of seconds to fill 5 gallons". I performed the test by letting the water from the spicket before the pressure tank run until the pump turned on, I let it run for 30 - 45 seconds before starting the test to equalize any affect from the pressure tank and ensure the pump was having to keep up.

I ran the test 2 times, 23.969 seconds first time, 24. 246 seconds the second time. Per this formula the GPM is around 12.5 GPM

 

[Reach4]

As I understand it, you got 12.5 GPM from one spigot? Cool.

That tells me your system could support a 12 GPM backwash.

I wonder if there are readily available 72 x 10 tanks for those who don't have 12 GPM available. That would need a ladder to do things, and would make brackets warranted even in areas with no earthquakes.

 

[Bannerman]

Dittohead's question regarding temperature is in relation to your water temperature, not the environment where the equipment will be located. Less GPM is required when using cold water to backwash as it is denser than warmer water.

Gravel is the most common underbed material. A Vortec distributor appears to be a great idea but I believe there may have been past issues with breakage of the distributor platform which then required replacement of the entire tank as the distributor cannot be removed from the tank.

The usual factor limiting filter size is related to the flow available to backwash the media. A larger diameter tank requires more backwash flow than a smaller diameter tank. While K-L is lighter in weight and therefore requires less backwash flow than most other media, the backwash flow requirements are substantial and must be adhered to. Often, a minimum backwash rate is specified which is not necessarily the optimal rate needed for long term performance and longevity of the media.

Here are some links to manufacturer information which includes US specifications:
http://www.watchwater.de/katalox_light/katalox_light.php
http://www.purewaterproducts.com/img/docs/manuals/Katalox-Light.pdf
http://www.watchwater.com/home/downloads/KL_operation_manual.pdf

Edited to add: When the filtering capacity required exceeds backwash capacity, two smaller filters can be used in parallel. That way, each filter can be sized within the backwash flow available as each would be programed to backwash at a different time than the other.

 

[ccroasmun]

Dittohead's question regarding temperature is in relation to your water temperature, not the environment where the equipment will be located. Less GPM is required when using cold water to backwash as it is denser than warmer water.

Gravel is the most common underbed material. A Vortec distributor appears to be a great idea but I believe there may have been past issues with breakage of the distributor platform which then required replacement of the entire tank as the distributor cannot be removed from the tank.

The usual factor limiting filter size is related to the flow available to backwash the media. A larger diameter tank requires more backwash flow than a smaller diameter tank. While K-L is lighter in weight and therefore requires less backwash flow than most other media, the backwash flow requirements are substantial and must be adhered to. Often, a minimum backwash rate is specified which is not necessarily the optimal rate needed for long term performance and longevity of the media.

Here are some links to manufacturer information which includes US specifications:
http://www.watchwater.de/katalox_light/katalox_light.php
http://www.purewaterproducts.com/img/docs/manuals/Katalox-Light.pdf
[URL='http://www.watchwater.com/home/downloads/KL_operation_manual.pdf[/QUOTE']http://www.watchwater.com/home/downloads/KL_operation_manual.pdf[/URL]

Thank you very much,

I realized he wanted water temp, was just provide environmental since I don't know the water temp at this time.....the fancy digital thermometer I have doesn't go below 90 somethin, guess they figure your dead below that.....lol

I will be posting temp, as I think about it I have a thermometer in my RV I use for charging the AC so I can get that in just a bit here.

It's good to hear lower temp requires les GPM because I bet it gets down to 38 - 40 at least in the pressure tank and exposed supply lines when we're in single digits.

If you have time, I'd love your opinion on how I tested GPM. I posted 3 more test results just recently and not sure if I'm off base on my numbers.