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hwk7072

wha? RO 50 vs. 100gpd - looks the same to me

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hwk7072

At this moment I'm looking at two RO Buddies side by side. One is 50gpd and the other is 100. Everything looks exactly the same - tubing same 1/4" (I thought that might be the difference, that the 100 would be maybe 5/8 or something), all canisters the same size. How could one be 50 and the other 100? Must be something simple I suppose. There's only about $10 difference.

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hwk7072

I get it. It seems that it's the RO membrane, nothing else, at least on this system. So if you buy a 50GPD you can make it a 100GPD merely by buying a 100GPD membrane next time.

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CronicReefer

What system are you planning on buying?

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hwk7072

RO Buddie with DI

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AZDesertRat

Most 100 GPD membranes are only 90% efficient so DI life is about 1/4 what it is with a 96-98% efficient RO membrane.

Honestly though I wouldn't waste my money on a small system that you wil end up upgrading so it actually works when you can ge ta true reef quality 90 GPD RO/DI from places like Spectrapure, BuckeyeHydro or PurelyH2o starting at around $130. The advantages are better RO membranes, better full size 10" sediment filters and carbon blocks in the correct micron ranges, better DI resin in a full size 20 oz refillable canister and cartridge and a inline pressure gauge. Spectrapure and Buckeye also use the much better capillary tube flow restrictors versus the fixed type that is rarely accurate.

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hwk7072

Good advice. I've been doing that a lot - try to save money up front, then end up buying higher quality so spending more than I would have initially. Thanks

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talwen

Yeah i always thought more GPA was better. But when i did alot of research the slower ones typically mean more life on membranes. I would go with one that can make the water you need in a resonable amount of time.

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AZDesertRat

The most popular RO membrane by far is the 75 GPD Dow Filmtec. It has the same rejection rate or removal efficiency as their smaller membranes but makes water up to 150% faster so less waiting around on water. Spectrapure starts with the Dow 75 for their systems then specially treats the membrane to increase its performance then either batch or individually hand tests them for quality control.

 

There is no advantage to a 25 or 50 GPD membrane since they usually cost about the same or more, are the same physical size, have the same efficiency but take much longer to make the same quality water.

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hwk7072

So based on this thread I canceled my RO Buddie and ordered a Spectrapure MPDI MaxPure RO and DI System - 90 GPD. Now I need to wrap my head around saddle valves and shutoff valves. Good videos on BRS for that. Ordered a shut off valve.

 

Here's a question, the instructions for the RO Buddie said that the input should be at 77°. That's not easy. It's impossible with a saddle valve connected only to cold water. Are others more lenient on input temperature?

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AZDesertRat

I hope that is their $124 refurbished system? The best value in reef quality RO/DI today. The only thing you need to add is a handheld TDS meter and whatever option you choose to hook it up which I mention below and which can be found locally at Lowes, HD or any hardware like Ace or True Value.

 

77 degrees is just a number the membrane industry agreed on to compare membranes against each other, it is NOT the ideal temperature. Just a standard like the 50 or 60 psi depending on the manufacturer.

 

In fact, colder water treats better and will give you lower RO only TDS and make your DI perform better and last longer. Never, ever, and I repeat, never try to blend hot and cold water to raise the temperature for an RO. This is the quickest way there is to ruin a membrane. I post this many times a year on all the reef forums, this is the third time in two days. Membranes are damaged by anything above 113 degrees which isn't all that hot. Remember being in the shower and someone flushed the toilet or started the washer or dishwasher? You got your tush scalded! Same thing happens to the membrane since it is about impossible to keep the temp constant.

 

My suggestion is to mount the RO/DI on the wall beside the washing machine and use a brass garden hose wye with the individual valves found in any garden section and hooked to the washer cold water supply. The valves let you isolate the RO/DI when not in use and you don't have to disconnect it.

 

If you are mounting it near or under a sink use a feed water adapter that fits on the faucets cold water supply angle valve so you don't have to cut any lines or permanently modify anything if you are renting.

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hwk7072

I paid full price, 190. Oh well. Thanks for letting me know about the temperature. That 77° didn't make sense to me.

 

Connecting to the washer hose is a good idea, I hadn't considered that. It will be mounted above a utility sink next to the washer, so I have some options. My concern about using hose type connections is leakage from the connectors like I get on outdoor hoses. I guess they just need to be good ones. Or maybe I'll just hire a plumber and he can figure it out.

 

Thanks for all of your knowledgeable advice.

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AZDesertRat

Mine has been hooked up with the wye for going on 13 years now and never leaked a drop. The RO/DI will come with the hose thread adapter so all you need is the wye, about $7-$8 at HD or Lowes in brass or bronze with the two ball valves built in. The waste line can be mounted so it drains into the sink drain. One huge advantage of mounting it near a laundry/slop sink is you can set your buckets or in my case 5G water jugs in the sink when filling so if you ever forget, not that I have ever done that or at least would admit to, well not more than 4 or 5 times my wife knows about anyway, it goes down the drain and not on the kitchen floor!

 

You might check Premium Aquatics or Marine Depot if you want the full priced Spectrapure system versus the $124 which is really the better deal by far. Both places offer free or reduced shipping and often have Spectrapure systems at a big discount. I am fortunate to live 30 miles from Spectrapure and can pick up locally because their shipping is a little steep.

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hwk7072

When you say wye, is that a Y connector?

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AZDesertRat

Yes, plumbing terminology says wye. One side with female threads screws to the cold water faucet or hose bib and the other two outlets have male hose thread fittings with individual ball valves.

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hwk7072

Nice. I even have a couple of those. Thanks

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hwk7072

If I might tap into your expertise one more time, how does one determine the psi, say at fully openl half open, etc.? Should I just open it up all the way?

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talwen

You can buy a cheap pressure gage and test it out. When I had my spectrapure it had one buit in. Its good to tie one into your system because it can help you tell when to change media.

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AZDesertRat

You shoud always fully open the faucet. Membranes love pressure and the higher it is the better it will perform.

Spectrapure RO/DI systems come with an inline pressure gauge as standard equipment but I add an additional inline pressure gauge before the sediment filter so I can monitor headloss across the filters as a way to monitor condition and plugging or fouling.

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hwk7072

Thanks, this is all's really valuable information.

 

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