GPD...What does it stand for?

[Son Of Skyline]

When looking at RO units, what does GPD stand for? Gallons per day?What does it mean to a buyer? How fast is 1 GPD?

For example, how many gallons of RO water per hour will a 10GPD RO unit fill vs a 50GPD unit?


Thanks in advance..

[Delphinus]

You got it ... gallons per day.

Although the actual flowrate depends on different variables, but basically when you're talking about a 24 gpd unit or a 50gpd unit you're talking about the size of the membrane. But whether you buy a 24gpd and actually GET 24 gpd when it's on, is going to depend on how old your filters are, and what pressure you run it at, and so on.

My "24 gpd" unit fills a 30g rubbermaid garbage can in about 12-16 hours.

[Seriak]

I believe, that given the correct pressure and temperature according to the suppliers specifications. A 24 GPD system will produce 24 gallons of water with continual operation every day. Therefore, it will produce 1 gallon every hour. So a 1 gallon would produce 1/24 gallons every hour and a 50 GPD would produce just over 2 gallon per hour. That you are more likely to achieve lower than this as optimal condition never occur in our homes. Who wants to run warm water through their RO and watch there energy bill go thrugh the roof.

[Delphinus]

Maybe I have a 50gpd unit and didn't even know it. LOL ... :smile:

[Seriak]

Maybe I have a 50gpd unit and didn't even know it. LOL ... :smile:

Or I could be completely wrong. And Tony, how dare you beet me to this post by only 1 minute.

Chris

[smokinreefer]

hey tony, whats your pressure at?
thats an awfully fast output for your 24gpd unit.

my 100gpd unit operates at 60psi and i fill my 30gallon garbage can in ~8hrs.

[Aquattro]

My 100GPD, when new, filled a 100g vat in almost exactly 24 hours. Pressure was 95PSI, temp was ~ 68F

[Delphinus]

I don't know ... ???? :neutral: Just regular household cold water pressure ... ????? :question: :confused: :question: How do I tell if I have a 50gpd unit then? Alls I know is, I bought my RO unit used, I put new filters and whatnot on it, and I thought it was a 24gpd unit but it takes way less than 24 hours to put out 24 gallons.

[Delphinus]

How are you guys measuring your water pressure?

[Aquattro]

How are you guys measuring your water pressure?

My unit has a pressure gauge inline.

[smokinreefer]

yup, me too.

[Son Of Skyline]

Thanks for the replies everyone. I guess I should avoid that Kent 10gpd unit unless I feel like waiting 12 hours for 5 gallons.

[Aquattro]

I guess I should avoid that Kent 10gpd unit unless I feel like waiting 12 hours for 5 gallons.

Exactly. My first unit was a 24 gpd and the waiting killed me. I can do a 5g jug now in about an hour and a bit.

[ed99]

I get just over 25 gpd off the tap here in Calgary with my 25 gpd rated RO unit. As mentioned in earlier posts the pressure and temperature of the water will affect the throughput. Warmer temperatures will mean higher throughput but also more slippage of the impurities you're trying to get rid of. Higher pressure will also give higher throughputs without hurting performance too much, but the membrane may not last as long if the pressure gets too high.

[Delphinus]

I must have a 50gpd unit then. I repeat my earlier question, how do I tell what membrane I have? Is there some kind of rule of thumb I can use, i.e., length or width of the RO membrane? (It's just some Kent RO unit. Note it's not RO/DI, I don't know if that changes things. Paid maybe $75 for it. I didn't think I'd get such a good deal that it'd be a 50gpd unit for that kind of coin.)

:question: :confused: :question:

[zulu_principle]

Why not just use DI water, RO seems like overkill especially if you are heating, and letting the saltwater mix properly.

[golden69_ca]

Delphinus if your it is truly a 24gpd ro you could have a rupured membrain our it could be in backwards . with filling a 30gal in 12 to 16 hours if everything was working tip top youd be at least a 60 gpd if not larger .

[EmilyB]

My in-line pressure gage here in Calgary has always read about 42psi.
Next time I am at Brad's I 'm going to have a shower. :lol:

[Jack]

I can get 82psi out my tap but I was told my membrane is rated for 80psi so I try to keep in a tad under.

[MitchM]

Tony, I've bought membranes before that said 25 gpd on the outside of the box, but the label that the bag that the actual membrane is in says 50 gpd.
I don't think that there is any indication what the rating is on the membrane cartridge itself.
Maybe you can tell a difference from the number of "wraps" of the membrane tissue or something....I dunno.... :question:

Mitch

[Delphinus]

Well, maybe I'll crack it open later today and see if I can find a rupture or if it's in backwards. If there's nothing like that I'll assume it's a 50gpd membrane. Or is it a bad idea to open it up?

[MitchM]

It won't hurt it to open it up....but those seals are tricky!

Mitch :wink:

[smokinreefer]

zulu,
care to explain a little?
i can understand that using just DI is not a problem for alot of hobbyist, and that RO may not be necessary for some, but what do you mean about the heating and mixing of the salt? i don't get it.