Nautilus FNS 48 overkill for my pool?

[Brentr]

I am thinking of changing my sand filter to a Nautilus FNS 48 DE filter. My water seems fine however I see particles floating at nite with light on. I also see dust when I brush and was just wondering if a DE filter would remove this. I can get this filter which is used for very little money however I would have to replace the grids. The filter is an older model and is black, not sure how old it is. Is this overkill for my pool. All thoughts are welcomed.

 

[linen]

It probably is overkill since our minimum recommendation is a ~15 sq.ft. DE filter for your pool. However, a filter that big should allow you to go a long time between backflushing/cleaning.

Have you tried DE in your sand filter? My experience is that it can filter those floaties you see in the water at night. The downside is, the filter needs backflushing more often.

 

[Keven]

There is no such things as over kill on filtration on a swimming pool. A black tank is 15 years or older.

 

[linen]

There is no such things as over kill on filtration on a swimming pool. A black tank is 15 years or older.

With the caveat that backwashing requirements go up with filter size. This is not such a problem with DE filters, but can be an issue with sand filters.

 

[Brentr]

It probably is overkill since our minimum recommendation is a ~15 sq.ft. DE filter for your pool. However, a filter that big should allow you to go a long time between backflushing/cleaning.

Have you tried DE in your sand filter? My experience is that it can filter those floaties you see in the water at night. The downside is, the filter needs backflushing more often.

Linen , I presently have added DE and I see no better results. My present filter is a Hayward pro series S220T

 

[linen]

Does the pressure go up as expected when you add the DE?

 

[Brentr]

There is no such things as over kill on filtration on a swimming pool. A black tank is 15 years or older.

Yes Kevin I think it is about 11 years old. How long should this tank last? I will be replacing the big o-ring and the filter grids. This filter has the valve assembly so I may be looking at replacing the spider gasket later on. What are your thoughts? thanks

 

[Brentr]

Does the pressure go up as expected when you add the DE?

Yes it does

 

[linen]

I am not sure you will see much better clarity then that (sand filter + DE) with a DE filter...hopefully someone who has made the direct comparison can comment.

 

[jblizzle]

Have you inspected / cleaned the sand?
Any chance you pump is too big for your filter and pushing the small particles through? I am thinking that could be part of the problem ... the 220T has a design flow rate of 52 GPM, and you could be above that with a 1.5HP pump. If you were going to upgrade something, I might suggest getting a 2-speed motor and running on low most of the time for better filtration.

There are many members here who have clear pools with sand filters. That said, most pools will show some stuff in the water at night with the lights on.

 

[Keven]

There is no such things as over kill on filtration on a swimming pool. A black tank is 15 years or older.

Yes Kevin I think it is about 11 years old. How long should this tank last? I will be replacing the big o-ring and the filter grids. This filter has the valve assembly so I may be looking at replacing the spider gasket later on. What are your thoughts? thanks

If it was my filter, I would inspect all the grids and clean them before purchasing new grids.. Also the money you could possible save by not having to replace grids I would just replace the valve. Filter tanks really don't have a average life, if it was maintained correctly and the sun didn't beat it to death it could possible last forever. That filter is know for leaking at the bottom where the lower pipe attaches to the bottom of the tank.


Hope this make sense I am trying to type this on my phone.

 

[Brentr]

Have you inspected / cleaned the sand?
Any chance you pump is too big for your filter and pushing the small particles through? I am thinking that could be part of the problem ... the 220T has a design flow rate of 52 GPM, and you could be above that with a 1.5HP pump. If you were going to upgrade something, I might suggest getting a 2-speed motor and running on low most of the time for better filtration.

There are many members here who have clear pools with sand filters. That said, most pools will show some stuff in the water at night with the lights on.

jblizzle, a 2 speed motor would not work as I have solar and the low speed would not be enough to prime panels. My pool is clear however I do see particles with the light on and I see dust when I brush the pool.

 

[Brentr]

There is no such things as over kill on filtration on a swimming pool. A black tank is 15 years or older.

Yes Kevin I think it is about 11 years old. How long should this tank last? I will be replacing the big o-ring and the filter grids. This filter has the valve assembly so I may be looking at replacing the spider gasket later on. What are your thoughts? thanks

If it was my filter, I would inspect all the grids and clean them before purchasing new grids.. Also the money you could possible save by not having to replace grids I would just replace the valve. Filter tanks really don't have a average life, if it was maintained correctly and the sun didn't beat it to death it could possible last forever. That filter is know for leaking at the bottom where the lower pipe attaches to the bottom of the tank.


Hope this make sense I am trying to type this on my phone.

Kevin, the owner tells me that one of the grids is torn so I was thinking of replacing all of them. Is there a gasket I can replace at the bottom where the lower pipe attaches to the bottom of the tank? Thanks

 

[Davegvg]

My answer to the nautilus FNS 48 being to big is no.

After a lifetime of pool ownership I agree with Kevins overfiltration/ bigger filter theory and install as a big a filter as I can fit.

Bigger filters are designed to flow more and typically lower your backpressure a bit just on install.
Bigger filter take longer to soil as well extending backwash times.

If you were happy with your filters prior performance you could just fix it (if possible) and keep it.

Any pool will show dust when brushing after some time regardless of its filter medium even with 24x7 pump runs you cant get all of it to the skimmer(s).

If you were never pleased with its performance you may consider zeobrite/ zeoX instead of sand.
Sand and DE works well for a lot of people - and it isn't too much of a hassle unless you backwash a lot and have to keep buying bags of de and find a place to put the muck.
Spent dirty DE is a really nasty substance.

I'm several months into zeo and have been very happy with its performance and find its filtration equal to the Quad DE 60 I was using with none of the cleaning hassles. Zeo only needs maintenance 1 once a year with an overnight soak of cleaner so although not totally maintenance free- pretty darn close.

Ill pay that price for DE clarity and sand ease of backwashing.

Zeo has on the order of 10X the surface area that pool sand does which is why it catches fines down to the same level.
If "unfolded" a single teaspoon would cover something like a football field of surface area.

Uncle Dave

 

[Brentr]

Uncle Dave I have decided not to buy the FNS 48 due to its age, however I am looking at a 2year old Hayward DE 4820. I will have to cut the in and out piping to the sand filter in order to inspect the sand. My issue is that over time the heavy sand filter has warped the plastic pad and it is sinking into the ground. I think that the sand filter is very heavy and the thought process is to replace it with a lighter filter. Do you think that the Hayward DE 4820 filter is lighter than a Hayward S220T sand filter?

 

[jblizzle]

The weight is in the water, so if the volumes are similar, they will probably weigh about the same.

 

[Brentr]

The weight is in the water, so if the volumes are similar, they will probably weigh about the same.

Jason sand weighs more than water and my filter has 250lbs of sand.

 

[jblizzle]

Only takes 30 gallons of water to weigh 250lbs, and that sand will reduce the amount of water in the filter. It is not exact, but a few pounds different is nit going to affect the flex of the pad much.

 

[Davegvg]

Uncle Dave I have decided not to buy the FNS 48 due to its age, however I am looking at a 2year old Hayward DE 4820. I will have to cut the in and out piping to the sand filter in order to inspect the sand. My issue is that over time the heavy sand filter has warped the plastic pad and it is sinking into the ground. I think that the sand filter is very heavy and the thought process is to replace it with a lighter filter. Do you think that the Hayward DE 4820 filter is lighter than a Hayward S220T sand filter?

I think you need to prep an area with cement block tiles or a concrete pad properly for this application before you do anything because a sinking piece of gear causes all kinds of other problems and is not how you end up with a "Trouble Free Pool".

Light = small and thats not what you want.

UD

 

[Brentr]

Uncle Dave I have decided not to buy the FNS 48 due to its age, however I am looking at a 2year old Hayward DE 4820. I will have to cut the in and out piping to the sand filter in order to inspect the sand. My issue is that over time the heavy sand filter has warped the plastic pad and it is sinking into the ground. I think that the sand filter is very heavy and the thought process is to replace it with a lighter filter. Do you think that the Hayward DE 4820 filter is lighter than a Hayward S220T sand filter?

I think you need to prep an area with cement block tiles or a concrete pad properly for this application before you do anything because a sinking piece of gear causes all kinds of other problems and is not how you end up with a "Trouble Free Pool".

Light = small and thats not what you want.

UD

That is my intention however moving this sand filter is not going to be easy