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Yet another RO unit thread

So I'm about to buy myself an RO unit (Whee!) and I'd like some input. Poking around the net, it seems reefers tend to highly recommend SpectraPure, so that's the brand I'm looking at. I am also planning on getting one with a DI cartridge so that when the day comes I finally set up a saltwater tank, I have that available - not to mention it doesn't add much to the cost.

Anyway, I've got two units under my crosshairs and I'd like input from those of you that are familiar with RO units.

SpectraPure MaxPure 60GPD RO/DI - $170.
SpectraPure CSP-DI 60GPD RO/DI - $240.

The differences I see are that the CSP-DI has .5 micron carbon and sediment filters while the Maxpure has a 1 micron sediment filter and a 10 micron carbon filter. The CSP-DI also has a TDS meter built in, but that means nothing to me as I have a separate TDS meter.

So, with that said, is it worth the extra $70 for the CSP, or should the Maxpure be fine?

Thanks in advance.
 
SpectraPure is a little expensive. Most reefers I know that are still using RO are using the Typhoon III model from airwaterice.com. Because I've a well, I don't really have a need since my TDS are comprised of almost 100% Calcium carbonate. Anyway, that is the unit I've had and used for years before I stopped dosing Kalk and just straight topped off direct from my plumbing. You might want to look into a different method, however. I've been hearing awesome things about Kold Ster-il units. They run at almost 4 gallons PER MINUTE, with 0 waste, 100% product water. You may, depending on your source water, want to add a DI canister to the end. Oh, and the canisters last 150,000 gallons, which averages out, for most people to about 2 years worth of use, not a few months. Currently, I don't have enough CPs to worry about it, a couple of gallons of DW per week works well for me at 89¢/gallon. But, if I expanded, or wanted to start a bog garden I could water with a hose, the Kold Ster-il is the unit I'd get.
 
I did look into the Kold Ster-il units, actually. Besides them costing more than I care to invest right now, I remember reading that they don't remove certain particulates, can't remember which. That might be solved by a DI canister, I don't know or remember. I'll take a peek at the Typhoon III, though, thanks!
 
If you are going to use it for cp and general use then a captive air tank is a very nice feature to have.... that way you have a few gallons ready on demand. Without the captive air tank the flow rate will be rather low.

Next step up from that is a permeate pump, this will extend prefilter life and increase system efficiency
Spectrapure is definitely a good brand, but neither of the two systems you posted would be what i would recommend for cp use (as packaged)

You can get a lot more bang for the buck IMHO

I have no personal experience with the KS unit, but looking at it from an engineering point of view i see several issues that would make me leary of it.

Plenty of threads on this subject, run a search...

Of course this is just my opinion based on my experience

my_rodi.jpg

RO/DI/PP/High pressure ASO system:
blue = permeate
blk = prefiltered water
yellow = brine
red = fresh water inlet
white = bladder tank
clear = system inlet and outlets

my_rodi_bw.jpg
 
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Okay, I'm confused on a few fronts here. First, the $240 unit is only $100 less than the Kold Ster-il unit. factoring in 3 membrane replacements and possibly 3 carts replacements, you're actually looking at spending about $100 MORE in the first two years of operation, not even counting your water bill. The second thing I'm confused on is how 0ppm TDS (or close enough to 0 to not make much of a difference), especially when a DI is used on the end, can be cause for concern from any point of view. Yeah, I've seen detractor threads, but none that ever offered any credibility beyond "theories". I know people already using these units for years, reefers all of them, keeping anything from softs to Acropora, consistently producing quality output with 0 waste water production. I fail to see how theories can trump actual practical experience, but such is the internet.
 
like i said i have no personal experience with the KS....

however, one of the features that make RO membranes last so long is their continous self cleaning... this is done via the waste water that is constantly flusing the surface of the membrane clean.

As i understand the KS unit boast of all the flow going through the filter, well in my reasoning this is another way of saying it has no self cleaning. When i look at the companys website it rated the system at 5000 gallons. But I didnt see at what input TDS this 5000 gallon life was based on.

Ive run my system for 6 or 7 years now and still on the second membrane and i put 25 dollars worth of prefilters on it every six months.
This is with a 100TDS inlet and a 0ppm TDS outlet with a 4:1 Brine ratio @50psig and several gallon per day usage
(my plants/humidifier/ice maker/drinking water)

Prtactical experience is what matters... I totally agree
Maybe someone with the KS system can chime in as well...
 
@KDodds: Whoa, slow down there, turbo. No need to get hot and bothered.

@Av8tor1: Oh, I've done plenty searching and it is for that reason I was hoping you'd find this. ;p
There are plenty of good threads here, especially your diagram - I'm sure that'll come in great handy once I have a unit - but none of them really touch on the details of what I was asking about the difference of .5 micron to 1 and 10 microns in the prefilters. But if you think I can get more bang for my buck and still get good reliability, then I'll definitely look elsewhere from SpecraPure. I wasn't planning on using a tank for two reasons: A) The only practical place I have to put it is in the kitchen and I don't know that there's enough room under the sink for it. The next place would be in the basement, but I'd rather not lug jugs of water up two flights of stairs every day. I was planning on just hooking it up to the sink, like I know swords does, and then putting it in a closet somewhere when I was done with it. And B) I just didn't think it would be all that much of an inconvenience to hook it up and leave it for a couple hours while it filled a 5 gallon jug since I don't plan on ever using it for drinking water. I can definitely see it being nice to have some water always on hand, though. If you think I can get a system with a tank and the pump for around the same price with a different brand, I might very seriously consider it. I'm looking to spend no more than ~$250 for the entire setup, but $250 is really pushing it. I'd be much more comfortable with $200.

Thanks for your input!
 
to be honest Reaper, most get them on ebay.... sure the filters that come with the unit may be on the cheap side, but youre going to replace those every six months or so.

What i do is make the first stage about 5 micron, then the second stage about 2 and final prefilter stage about 1 or .5 if you wish... that way each prefilter is sharing the load

If you make the first prefilter .5 micron the following filters really dont do much... so you end up with much less "capacity"

The holding tanks are nice, if it was anyway possible i would get that feature.... it cost too much to add one later (shipping/aso valve etc)

look on ebay and you can find holding tank kits for less then 200 easily... just find a vendor who will answer your questions, has a good feedback and one that gives you the warm and fuzzy feeling

for a little over two you should be able to get the tank and permeate pump ( those are nice, i love mine... that is how i get 6m out of prefilters)
 
Will do. I'm not sure what kind of questions to ask a seller, though, haha.

I've got a question for you, though: how many stages is yours? I would guess 5 or 6, but I might be crazy.
 
  • #10
3 stages of prefiltering, first is sediment only and next two are carbon block.
Then the RO membrane and DI then a final carbon filter which is fed post holding tank

It would be called a 3 stage with DI I guess (some might call it 4 or 5)

Questions to ask

Does it include a bypass valve for cleaning (yes is desirable)
Are the DI beads replaceable or is it a cartridge ( I like replaceable, cheaper to maintain)
What size is the ASO valve (90% is nice for permeate pump systems, 60 is normal for non)
What is the suggested brine rate (4:1 is common)
etc.

some of these questions is just to see if the vendor knows what he is talking about
 
  • #11
Alright, looking through some ebay postings, I'm seeing a lot of units that look quite similar to yours but are being called 6-stage units. I am having trouble finding one with a permeate pump, too, but lots with the holding tank for pretty cheap.

This is the dominating one on ebay right now, seller has good ratings. Again, though, no permeate pump.

I might also note that my tap water is about 60ppm, so I'm not looking at a terrible starting place. As I understand it, that should increase the efficiency of a system for me, right?
 
  • #12
that looks like a very respectable unit, it does have the RI beads/tank/cleaning bypass valve... etc, you might contact him and see if they can add the permeate pump if you want it

60ppm will make life very easy on your system and the membrane and DI beads will last a long time
 
  • #13
Excellent, I'll contact the seller, then, with some questions and report my findings.

You're awesome, thanks for all the input.
 
  • #14
I'm neither hot, nor bothered. This is just something I know quite a bit about and with which I have had a great deal of experience as an aquarist and on the retail end (many moons ago). I was just curious as maybe you weren't aware of the specs and pricing and running costs, etc. Now, if you have SUPER hard water, you'd definitely need a DI on the end as the Kold Ster-il unit does not strip the most common contents of hard water, Calcium and Magnesium. This WILL increase your costs, so pegging down to 0 TDS (or less than 50), depending on your water supply as I said before, may be more worth the RO. But if all you want to outlay is in the range mentioned, it's a moot point. In that case, the Typhoon II is also out of your range, but only just. Keep in mind it's a 150gpd unit and includes amenities most systems don't, like auto shut-off, TDS alarm and in-line metering, float valve (for filling vats, I use Rubbermaid Roughnecks, bulkheaded and PVC'd in an array of 4 32g cans), saddle valve, drain saddle, etc. Using this unit, I've been able to keep my 400ppm source below 50ppm for over a year, under 10ppm for about 9 months, without replacements. If your goal is 0ppm, I'd suggest a 6-9 month replacement schedule of ALL parts, membrane and filters.

I'm fairly certain that the 5,000 gallon calculation is a mistype somewhere (and from what I remember, is based on whole house use, anyway). Each Kold Ster-il cart is rated for 150,000 gallons to ANSI/NSF Standard. Hardness/Alkalinity doesn't really play into that lifespan as it has no effect there anyway. But it would play into the kati/ani end, where you might find, again depending on your source water, that RO is more effective (cheaper) than replacing DI carts.

Anyway, moot all of it as you've found your unit I guess, but this might be helpful to others who might read it, either way.
 
  • #16
Okay, it just seemed like you were coming in on a pretty high horse and discounting all the rest of the internet's opinion, regardless of source and not even bothering to ask for a source (not that it would've mattered 'cause I can't remember XD ). Obviously a misunderstanding.

I would certainly be willing to give KS units a closer look if not for the cost. Unfortunately, I'm not buying an RO unit out of want, but necessity. My wife and I are going on a 3-week vacation this summer and leaving a good friend of ours with a key to take care of the plants. She's already doing so much for us, I could never ask her to run to the grocery store every few days to refill a ton of water jugs. That said, I can't afford to spend the money a KS unit demands right now. I'm very well aware that the long-term cost could be far less than an RO unit in terms of waste and whatnot and I am the first one to jump on an investment, but again, I simply cannot afford to spend that kind of money right now and, right now, I need something. So RO it is. ;p
 
  • #17
If that's the case, you may want to invest in a very low gpd unit. Quality of the unit (and initial filters/membrane, which are standard and can be replaced with higher quality later, if desired) shouldn't be an issue as they're all pretty much just plastic canisters, gaskets, and JG fittings/tubing. I'd forget the drinking water option (pressure tanks create a less efficient environment) and invest in one or two (round) rubbermaid cans (with tops to protect purity). Your housesitter will then be able to lift the lid, fil a jug or watering can, and go to it, easy as pie. A float valve will prevent overflow. A couple of 2" bulkheads, some silicone, and a small lenght of PVC pipe will daisy-chain them together, also lending to an open ended system that can be added to easily, as needed, especially if you put ball valves between cans.
 
  • #18
My understanding is that the permeate pump solves the issue of equalizing the pressure across the membrane and, thus, low efficiency with a tank. And I think I might be pushing my limits (space-wise) with a 4.5 gallon tank, let alone some rubbermaids. While that would obviously be ideal, I just don't have anywhere to put that much stuff, unless I want to hike up two flights of stairs from my basement to the plant room carrying jugs of water all the time (which, I assure you, I don't, LOL).
 
  • #19
Oh crap, I just remembered... I need to soften my tap for my Discus tank, but didn't want to go with reconstituting water. Soooo... this being a temporary situation, like yours, I went with filling the tank with tap and then rigging a pump to recirculat through a "Tap Water Filter" (Aquarium Pharmaceuticals). $30. It's just a DI, so long term, not cost effective. But, short term, with a faucet adapter included, it might very well work for you and be a lot cheaper than an RO unit.

---------- Post added at 12:42 AM ---------- Previous post was at 12:39 AM ----------

unless I want to hike up two flights of stairs from my basement to the plant room carrying jugs of water all the time (which, I assure you, I don't, LOL).

ROFL, same situation here, I just ran the RO up to the tank (one floor) on a tee for top-off, but eventually moved said tank's sump through the floor to the basement (much quieter). Anyway, for the record, if the RO is in the basement, you CAN run it up 10' vertical to a holding bin, if you wanted or needed to do so.
 
  • #20
Reaper...

Exactly, if you dont go with the pressurized holding tank then do not get a permeate pump, it is beneficial for captive air (Accumulator) tank based units only

Your installation requirements may trump some of the other considerations... but you have enough understanding to make the right call based upon your specific needs mate

Regardless of the system you choose, if I can help just hollar :)
 
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