Valve between pump and filter.

[CarlD]

I suspect you're going to burn out your pump motor faster and possibly increase your electrical usage. A lower capacity impeller or a two-speed motor would be a better solution.

Or a bigger sand filter. If it's a 1.5 hp Superpump or other IG pump you probably should have a 250-300 lb sand filter.

[swimdaddy]

Ok, that's what I was wondering. My filter normally runs at 16 PSI, and with the ball valve I drop that to about 12 PSI and that seems to work well, but if I burn out my motor I'll be wishing I had upgraded the pump or filter. I was looking for the cheap fix.

[CarlD]

I dunno. But you MAY be able to lower the speed of the motor with a transformer. I don't know how well or safely that would work, but that would be like a 2 speed pump. Still, it could burn it out as well. Have to find an expert on electrical motors.

[swimdaddy]

I have often wondered if you could use a simple rheostat to control the speed of the motor, like any other electric motor used in electronics. Heck, even my electric chain saw runs faster or slower depending on how far I pull the trigger.

[Anonymous [GDPR] European in the UK]

Ok, that's what I was wondering. My filter normally runs at 16 PSI, and with the ball valve I drop that to about 12 PSI and that seems to work well, but if I burn out my motor I'll be wishing I had upgraded the pump or filter. I was looking for the cheap fix.

I would recommend buying another filter, the same filter you have now and connecting them both into service. This will double the surface area of filtration whilst keeping reasonable sized plumbing into each. This is preferable to have to try and sell off your filter and buy a single one slightly larger. I would have put that down as the cheapest fix.

[CarlD]

I must admit I am baffled by how you would plumb in 2 sand filters unless they are both side-mounts and you use a single multi-port valve for both, and then it would probably need to be a larger and more expensive one. Otherwise I don't see how you could do it with 2 top mounts because of the multi-port valves. I guess they could be parallel, but then EVERY function would need to be duplicated on each, especially back-washing and you'd need to shut one down, than the other.

Comparing Hayward top-mount sand filters (Pro-Series):
An 18" (150#) filter runs about $230.
One with 22" (200#) runs about $250.
And a 24" (300#) runs about $380.

So I fail to see how a second 18" filter is cheaper than replacing it with a 22" or 24" filter. Plus if the 18" can be sold, even for far less, it offsets the cost of the bigger filter.

[Anonymous [GDPR] European in the UK]

I have plumbed in two filters using side mounts and dual multiports and also on others gate valves to separate as you say for back washing. Top mounts could still be done. Takes a little outside the box thinking. The costs are quite a bit different to over here so I see your point but for the size of the pool and pump increasing the area of filtration will bring the water quality up as is already noted by valving the pump flow down.

18" gives an area of around 0.17m but a 24" is only 0.29m (sorry my spec is in meters) at $380 for a 24" and assuming original sold at 50% $115 the cost would be net $265 and you'd still have the smaller filter area. It does seem big pumps and small filters are the norm in the USA compared to Europe.

[CarlD]

I have plumbed in two filters using side mounts and dual multiports and also on others gate valves to separate as you say for back washing. Top mounts could still be done. Takes a little outside the box thinking. The costs are quite a bit different to over here so I see your point but for the size of the pool and pump increasing the area of filtration will bring the water quality up as is already noted by valving the pump flow down.

18" gives an area of around 0.17m but a 24" is only 0.29m (sorry my spec is in meters) at $380 for a 24" and assuming original sold at 50% $115 the cost would be net $265 and you'd still have the smaller filter area. It does seem big pumps and small filters are the norm in the USA compared to Europe.

Yes, it's incredibly stupid and something Ben Powell has been challenging for many years. You can see his tip "The Bigger Pool Pump Scam" on his other web site, PoolSolutions.com which he started 19 years ago. I don't know how old the article is, but it was there when I found the site in 2000. It has been a constant frustration for us over the years.

Filter prices definitely, like any decision, factor in. Here, the difference between a 150# (18") filter and a 300# (24") filter is only $150--less than ₤100 for essentially double the capacity. Plus for SwimDaddy's pool, 300# would EASILY meet his needs even with a too-big pump. And, if he can sell the old filter for $100, that's 2/3 of his cost differential between another 150# vs a 300#.

Personally, unless the filter is damaged, I'd go with down-sizing the pump and getting a 2spd. VS pumps are very expensive still, and if you do NOT have a good surge suppressor they'll get zapped. I don't know if they yet make the cut-off suppressors for them. These are sold for appliances and won't come on if you are having a brown-out (low voltage) which zaps electronics as badly as surges.

[swimdaddy]

I have thought of getting another similar sized filter and plumming them in parallel, but decided it wasn't a good idea, more of a hassle. Have been scoping ebay for a larger 24 or even a 27 inch filter for next season.

I will also someday be looking for a VS or 2spd pump, but for now I think the filter is more of a priority. Maybe you all can confirm or dismiss my conclusions. When you vacuum with a suction side vacuum using a 2 spd pump, you use the higher speed, right? Doing that with my filter pushes the dirt right through. I can vacuum better with DE in the filter, but the filter is so small it clogs up pretty quickly (lots of dust and smoke where I am at right now). I hate vacuuming to waste because of wasted chemicals. My hope is that a bigger filter with or without DE will allow me to vacuum through the filter.