Will this pump work?

thegame9377

Well-known member
Jun 3, 2012
50
Louisville, KY
#1
So we closed on our new house today, which has a pool and needs a new pump/filter. I found a really good deal on a 1.5HP, 2 speed Jandy Flo Pro pump. Can anyone advise if this is a decent pump for my pool and that it's fine for an in-ground pool?

This is the pump here, but I have one I can buy new for $350 cash locally: http://www.poolsupplyworld.com/poolsupp ... M1.5-2.htm

Also wanted to check that it would be o.k. to pair with a Hayward S310T2 sand filter?

As for the current set-up at the pool, I have no clue what they are. Both pump and filter look 10+ years old, are non-functioning (pool has been sitting for a few years and this was an estate sale), and the plates with the brand/model numbers are all just rusted and illegible. :(

Thanks in advance for the help, guys!
 

linen

TFP Expert
LifeTime Supporter
Jul 30, 2010
8,649
Twin Cities, MN
#2
Without more information about your plumbing, pool features, etc. we can't say much about that pump for your pool, though it looks to be a good match to that filter (though plumbing plays into this too).

As for the filter...it is undersized for your pool at 4.9 sq. ft.. We would recommend a minimum of 7.0 sq. ft. sand filter for that pool size... so a S360T2 would be a better fit for your pool.
 

thegame9377

Well-known member
Jun 3, 2012
50
Louisville, KY
#3
linen said:
Without more information about your plumbing, pool features, etc. we can't say much about that pump for your pool, though it looks to be a good match to that filter (though plumbing plays into this too).

As for the filter...it is undersized for your pool at 4.9 sq. ft.. We would recommend a minimum of 7.0 sq. ft. sand filter for that pool size... so a S360T2 would be a better fit for your pool.
I'm kind of a n00b at this, so I'll try my best regarding plumbing. It has a pump line and a return line right by the current pump/filter. They're black poly pipe, so yeah, that will be fun to connect to PVC fittings. Not really much else plumbing - no waterfalls/spas or anything like that.

As for the filter, I thought everything was based on flowrate? The s310t2 has a 98GPM flowrate, which would be enough to turn over all 38,000 gallons within 6 hours (if my math is correct). Isn't that enough?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,911
SouthWest Alabama
#4
With filters the larger the better (up to a point on a sand filter). It slows down the flow through the filter and therefore traps smaller particles because they're not getting blown through the filter by high speed flow. The flow rate listed on the filter is just the maximum rated flow it's not what the filter actually sees. That depends on the plumbing and the pump. If you have poly pipe you're most likely not going to get close to 98 gpm through it.

The Flo-Pro is a good pump but with your plumbing you'll probably be between 50 and 70 gpm.

What size is the piping?
 

linen

TFP Expert
LifeTime Supporter
Jul 30, 2010
8,649
Twin Cities, MN
#5
Yes, please post some details on piping diameter, and approximate length of run from the pool. That filter size I pointed you at needs at least ~90 gpm to backwash properly.
 

thegame9377

Well-known member
Jun 3, 2012
50
Louisville, KY
#8
Bama Rambler said:
With the insert fittings on poly pipe I'll stick with my original estimate of 50 to 70 GPM.

So does that mean I should go with the smaller of the two Hayward filters discussed above because I won't have enough flow rate to backwash with the larger one?

Thanks again for your help!
 

linen

TFP Expert
LifeTime Supporter
Jul 30, 2010
8,649
Twin Cities, MN
#9
As Bama mentioned, with your plumbing fittings (the barbed fittings that fit inside the poly pipe), I think your piping is going to limit the flow rate, so although you pool would benefit from a larger filter, it will be difficult to get the flow rate needed (due to the head loss of the piping, etc.) to get a proper backwash. Hayward states that you need 60% of the design flow rate of the filter to get a proper backwash, which in the case of the S360T2 is 141 gpm*.6= 85 gpm (verses 98 gpm *.6 = 59 gpm for the S310T2). Even on backwash (which would have less head loss) that pump may not be able to do that.

Ideally, I would suggest staying with the larger filter and choosing a different pump such as the 2 Hp 2-speed version of the flo pro ...but in the real world there are things called budgets :cry: The down side to the smaller filter is you will have to backwash it more often, but it should still work for your pool with the pump you have mentioned.
 

thegame9377

Well-known member
Jun 3, 2012
50
Louisville, KY
#10
linen said:
As Bama mentioned, with your plumbing fittings (the barbed fittings that fit inside the poly pipe), I think your piping is going to limit the flow rate, so although you pool would benefit from a larger filter, it will be difficult to get the flow rate needed (due to the head loss of the piping, etc.) to get a proper backwash. Hayward states that you need 60% of the design flow rate of the filter to get a proper backwash, which in the case of the S360T2 is 141 gpm*.6= 85 gpm (verses 98 gpm *.6 = 59 gpm for the S310T2). Even on backwash (which would have less head loss) that pump may not be able to do that.

Ideally, I would suggest staying with the larger filter and choosing a different pump such as the 2 Hp 2-speed version of the flo pro ...but in the real world there are things called budgets :cry: The down side to the smaller filter is you will have to backwash it more often, but it should still work for your pool with the pump you have mentioned.
I appreciate the detailed info guys. That helps me understand much better!
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,183
Pleasanton, CA
#11
linen said:
Hayward states that you need 60% of the design flow rate of the filter to get a proper backwash, which in the case of the S360T2 is 141 gpm*.6= 85 gpm (verses 98 gpm *.6 = 59 gpm for the S310T2).
Was the 60% number from a Hayward rep or is that on a spec sheet?

My theory has always been that a sand filter should backwash properly if the backwash flow rate is higher than the normal filter flow rate which is almost always true because there should be less return head in backwash mode than filter mode. However, I have no data to back it up although there are plenty of people on the forum who have very large sand filters with very small pumps so there is some evidence that this is probably true.

Also, I don't think the filter needs to be purged of all dirt when cleaning. As long as the pressure drops to where it was when it was new, I would say that is good enough and probably any flow rate can do that it may just take longer with lower flow rates.

Having said all that, the FloPro can get above 80 GPM with low head loss so it might meet the spec anyway.
 

linen

TFP Expert
LifeTime Supporter
Jul 30, 2010
8,649
Twin Cities, MN
#12
mas985 said:
Was the 60% number from a Hayward rep or is that on a spec sheet?
Not such a good source :oops: It was out of their FAQ section:
Your pump may be too small to provide sufficient flow for proper backwashing. Your filter will filter properly, but if your pump does not supply at least 60% of the filter’s designed flow rate, you filter will never backwash completely. Refer to the label on you filter for flow rate requirements. It may be necessary to upgrade the pump or downgrade the filter.