stonepilot
Member
which do you think is best, I only loose about 2.5 gallons a day but willing to pay for a good unit.
Best RO/DI
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burning2nd
Well-known member
www.thefilterguys.biz
and the best part is you can call, and get the guy who owns it.
great service, warrenty, pritty good priceing 2
and the best part is you can call, and get the guy who owns it.
great service, warrenty, pritty good priceing 2
james734
Well-known member
Not sure about the best but I just bought one off of ebay from FilterDirect. I think it's just as good as any of the others out there.
http://cgi.ebay.com/AQUARIUM-2-110G...hZ002QQcategoryZ20756QQtcZphotoQQcmdZViewItem
http://cgi.ebay.com/AQUARIUM-2-110G...hZ002QQcategoryZ20756QQtcZphotoQQcmdZViewItem
I like my seachem pinnacle + 100gph....it's over 2 years old, ( I bought it in June of '05 when it was already a year old) and still returns water with a TDS of less than 3 on the same filters...and thats with a tap water reading of 400 going in...
MikeS
MikeS
burning2nd
Well-known member
WOW 400 going in. i would think that, that would make your filters go quicker.
i try no to run mine when im close to 100, i like to be down about 47ppm
but i did notice one thing, when other water applacation are one in the house
(sink, dishwasher, water hose out side big time) the ppm will drop from close to 100 (in mornings uselly after water sits in pips all night) to 50 45 somewhere around there,
after a long day of water the lawn the ppm in the house is like 15.
i try no to run mine when im close to 100, i like to be down about 47ppm
but i did notice one thing, when other water applacation are one in the house
(sink, dishwasher, water hose out side big time) the ppm will drop from close to 100 (in mornings uselly after water sits in pips all night) to 50 45 somewhere around there,
after a long day of water the lawn the ppm in the house is like 15.
yes, I'm suprised the filters and RO membrane have held up as long as they have in my unit. I used to have it hooked up behind a water softener at the other house, but I don't have one where I am living now, so it gets fed straight tap water. I've been here a year, and it is still giving me a 2-3 TDS final product...
MikeS
MikeS
i'll second that..this is a good unit..i bought the other one from them ..i need it for drinking water also, so i got this one..it has a sink faucet and storage tank with it..you can always change out the last filter and replace it with another DI canister...
http://cgi.ebay.com/WaterGeneral-RO...hZ002QQcategoryZ46310QQtcZphotoQQcmdZViewItem
burning2nd
Well-known member
I would contister adding 2 Di cart's
and maybe changeing your membrains even 2-3 Tds is enought to make algae nightmares
and maybe changeing your membrains even 2-3 Tds is enought to make algae nightmares
stonepilot: I have followed many RO/DI threads and this one from spectrapure is one of the highest recommended (some have touted it as 'the best'): http://www.spectrapure.com/St_MaxCap-RO-DI.htm
FWIW, it is not what I have. I have the Optima automated from purelyh2o.com & so far it's worked very well: http://www.purelyh2o.com/product.php?productid=16135&cat=249&page=1
However, if I was buying again, I might very well get this one. When it's time to replace my filters, I will be getting them from spectrapure.com.
RO/DI units from www.thefilterguys.biz, www.airwaterice.com, and www.buckeyefieldsupply.com are also highly recommended by many folks.
Some of those companies are so good they will pull up the water report for your area (assuming it's available online) and recommend a unit for you. Some areas treat their water with different chemicals (chloramine for example), so that could influence what RO/DI unit would be best for you. It might be worthwhile to email these various companies and describe to them what you're after, etc and see what they recommend. IMO, the ones that respond quickly and with some knowledgable information would be other deciding factors to me on which unit/company to go with (good customer service).
hth,
rob
FWIW, it is not what I have. I have the Optima automated from purelyh2o.com & so far it's worked very well: http://www.purelyh2o.com/product.php?productid=16135&cat=249&page=1
However, if I was buying again, I might very well get this one. When it's time to replace my filters, I will be getting them from spectrapure.com.
RO/DI units from www.thefilterguys.biz, www.airwaterice.com, and www.buckeyefieldsupply.com are also highly recommended by many folks.
Some of those companies are so good they will pull up the water report for your area (assuming it's available online) and recommend a unit for you. Some areas treat their water with different chemicals (chloramine for example), so that could influence what RO/DI unit would be best for you. It might be worthwhile to email these various companies and describe to them what you're after, etc and see what they recommend. IMO, the ones that respond quickly and with some knowledgable information would be other deciding factors to me on which unit/company to go with (good customer service).
hth,
rob
burning: what you're describing is common for the water that's been standing in the pipes. In fact, everytime you use a RO/DI unit, the water that initially comes out will most likely have a higher TDS reading until the water that was standing in the RO/DI unit has run through. This is why it's generally a good idea to discard the initial water that comes out of the RO/DI, and/or run the RO/DI unit for extended periods of time instead of short on/off bursts.
When taking tds readings we should do the same. Let the tap, ro, or rodi water runoff for a while before taking the sample....this will give a more representative reading of what the tds is, not just what comes out first.
hth,
rob
I test the output water monthy for phosphate and nitrate, both are undetectible...as long as they stay that way, I'm not going to worry about 2-3 ppm TDS....with 400 TDS going in, that's a 99.3%-99.5% rejection rate of TDS anyway...
MikeS
Reefbound
Well-known member
This is the one I have, Why should the fish be the only ones to benefit...
http://cgi.ebay.com/WaterGeneral-RO...hZ002QQcategoryZ46310QQtcZphotoQQcmdZViewItem
TDS meter says 99 in and 0 out... you cant get better than 0. I dont see a need for duel DI cans...
http://cgi.ebay.com/WaterGeneral-RO...hZ002QQcategoryZ46310QQtcZphotoQQcmdZViewItem
TDS meter says 99 in and 0 out... you cant get better than 0. I dont see a need for duel DI cans...
What is most important is what the filter is actually removing. Most have one or two carbon prefilters, these will remove a lot of the chlorine and chloramine going into the unit, as well as some of the phosphate and nitrate. The RO membrane will remove most of the rest. The addition of a DI canister to a unit not already equipped with one will further remove problem substances such as nitrate and phosphate, purifying the final product.
The water going into the unit has a lot to do with the final product as well. If you live in an area where your tap water is high in nitrate and phosphate in particular, you may want to invest in a DI canister or get a unit that comes with one. Test your output water periodically for both of these, it will let you know if you need more filtration. Many areas are fine with RO alone...
MikeS
The water going into the unit has a lot to do with the final product as well. If you live in an area where your tap water is high in nitrate and phosphate in particular, you may want to invest in a DI canister or get a unit that comes with one. Test your output water periodically for both of these, it will let you know if you need more filtration. Many areas are fine with RO alone...
MikeS
Mike: I disagree with you on just a slight point. You say "many areas are fine with RO alone", and while I do not disagree that RO is definitely better than plain old tap water, I think everyone, regardless of what area you live in, will benefit from having RO & DI. The reason is this:
Typically a good RO membrane with have 98% rejection rate. It varies from brand to brand, and from membrane to membrane, but on average... So, for a person that lives in an area with above average tap water (say Seattle, for instance), the incoming tap tds might be 50ppm. 98% rejection rate would mean after the RO membrane, the tds is down to approx 1ppm. Going through a DI resin will bring the tds down to 0, or very close.
If another person lives in an area with say 200ppm tds at the tap (4 times worse), after the RO, the tds would be approx 4ppm. After going through the DI resin, the tds would be down to 0, or very close. The difference for this person is the DI resin is going to be exhausted much quicker, approx 4 times faster. But the final product will be pretty close to the guy in seattle.
Basically I think the full RO/DI setup is worthwhile for everyone, regardless of where they live. The DI takes whatever the RO membranes misses, so it is always beneficial since no RO membrane has a 100% rejection rate.
Rob
dragoneggs
Well-known member
Hi Rob,
I can't argue with you that the DI unit will further purify the water past what eh DO unit is capable of... I think one must look at what you are getting for the money. It boils down to the law of diminishing returns. DI replacement/maintenance is costly.
I am no expert in water quality so I can't comment on the 'worthiness' of a DI system but I would be interested in actual benefit of RO/DI vs. RO only... not just 0 vs 1 TDS but actual effect to the ecosystem.
Mark
I can't argue with you that the DI unit will further purify the water past what eh DO unit is capable of... I think one must look at what you are getting for the money. It boils down to the law of diminishing returns. DI replacement/maintenance is costly.
I am no expert in water quality so I can't comment on the 'worthiness' of a DI system but I would be interested in actual benefit of RO/DI vs. RO only... not just 0 vs 1 TDS but actual effect to the ecosystem.
Mark
Hi Mark: yup, I cannot argue with you either on your point of diminishing returns. It is definitely in no way a situation where a $200 unit is 2 times better than a $100 unit. But it probably is better by some degree. So a person's personal budget, etc are certainly factors that play into the equation.
I am no water expert either, but here's my understanding of the whole tds thing. (As you are probably aware,) tds is total dissolved solids. This tds is not necessarily bad, but it could be. tds can be detected because the dissolved solids have some small electrical charge. The more charge, the higher the tds. In actuality, tds meters just produce an approx tds reading based on the electrical conductivity (EC) of the water. The EC is absolute and can be measured. The tds is an approximation, based on the EC. This is because different solids have different charges. Copper versus soil, or similar, if you get my point. There's no true way to determine what the actual chemical makeup of the tds is, except to evaporate 100% of the water and then analyze the remaining solids for chemical makeup. Of course, that is beyond the means of most.
So, the question is, is 0 tds absolutely necessary? Or is 1 tds ok. or 10 tds. That answer is going to be different for everyone, because it basically depends on what is in your tds. If it is something that is very detrimental to a reef (such as copper), it's in your best interest to eliminate as much as you can...all of it if that is possible. But, if it's something non detrimental (maybe calcium or something), then it's no big deal. 10tds of calcium would be fine, right? But since it's really quite difficult for us to truly know what the makeup of the tds is, it makes sense (to me at least) to try and eliminate all the tds. If I can get it down to 0, then I add in what I want (i.e. salt, maybe some alk or ca supplement, etc).
Anyways, it's kind of a crap shoot I guess. Much like using tap. A lot of people give the advice not to use tap, but in reality there are folks out there that do & seem to have perfectly fine reefs. For them, they see no return at all from RO or RODI unit. My point would be just that there is a benefit from using the DI, just as I would argue there's a benefit for using RO. It certainly may be a diminishing return situation, but regardless of that it is beneficial to everyone. And, afterall the title of the thread is 'Best RO/DI'
So, just my .02
Rob
I am no water expert either, but here's my understanding of the whole tds thing. (As you are probably aware,) tds is total dissolved solids. This tds is not necessarily bad, but it could be. tds can be detected because the dissolved solids have some small electrical charge. The more charge, the higher the tds. In actuality, tds meters just produce an approx tds reading based on the electrical conductivity (EC) of the water. The EC is absolute and can be measured. The tds is an approximation, based on the EC. This is because different solids have different charges. Copper versus soil, or similar, if you get my point. There's no true way to determine what the actual chemical makeup of the tds is, except to evaporate 100% of the water and then analyze the remaining solids for chemical makeup. Of course, that is beyond the means of most.
So, the question is, is 0 tds absolutely necessary? Or is 1 tds ok. or 10 tds. That answer is going to be different for everyone, because it basically depends on what is in your tds. If it is something that is very detrimental to a reef (such as copper), it's in your best interest to eliminate as much as you can...all of it if that is possible. But, if it's something non detrimental (maybe calcium or something), then it's no big deal. 10tds of calcium would be fine, right? But since it's really quite difficult for us to truly know what the makeup of the tds is, it makes sense (to me at least) to try and eliminate all the tds. If I can get it down to 0, then I add in what I want (i.e. salt, maybe some alk or ca supplement, etc).
Anyways, it's kind of a crap shoot I guess. Much like using tap. A lot of people give the advice not to use tap, but in reality there are folks out there that do & seem to have perfectly fine reefs. For them, they see no return at all from RO or RODI unit. My point would be just that there is a benefit from using the DI, just as I would argue there's a benefit for using RO. It certainly may be a diminishing return situation, but regardless of that it is beneficial to everyone. And, afterall the title of the thread is 'Best RO/DI'
So, just my .02
Rob
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Mark: one more thing came to mind in regards to the diminishing returns that I wanted to point out. If the argument is that someone with 1tds of RO water may not get as much 'value' out of the DI versus someone that has say 7tds of RO water, don't forget that the same DI resin is going to last the guy with 1tds 7 times longer than the other guy. So while there is still a cost associated with replacement/maintenance, that cost is pretty much in ratio to how much the DI is being used.
The above principle is also one of the main arguments to why a quality RO membrane is better than a lesser quality RO membrane. DI resin will basically absorb remaining tds by deionizing process. So a RO membrane that only rejects maybe 94% will still come out close to 0 after the DI, but the difference is that the DI resin will be exhausted much faster than the 98% rejection rate of the better membrane (approx 3 times faster). This is why it's usually recommended to check the tds after the RO in addition to after the DI. High tds after the RO means you're membrane and/or pre filters may need replacement, and also that your DI is going to be used up quickly. High tds after the DI means your DI needs to be replaced.
The above principle is also one of the main arguments to why a quality RO membrane is better than a lesser quality RO membrane. DI resin will basically absorb remaining tds by deionizing process. So a RO membrane that only rejects maybe 94% will still come out close to 0 after the DI, but the difference is that the DI resin will be exhausted much faster than the 98% rejection rate of the better membrane (approx 3 times faster). This is why it's usually recommended to check the tds after the RO in addition to after the DI. High tds after the RO means you're membrane and/or pre filters may need replacement, and also that your DI is going to be used up quickly. High tds after the DI means your DI needs to be replaced.
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DonW
R.I.P.
I really doubt dimishing returns is a good reason not to use a rodi, with the cost of a refill being $8 and the cost of a add-on unit $30 full and ready to go. I think it really boils down to what is working for the individual user and hobby experience. Its real easy to take the tds and water chemistry so far that it takes the enjoyment out of the hobby. If its not broken why fix it?
Don
Don
dragoneggs
Well-known member
Rob and Don... All good comments. I am currently setting up an RO system that will be located in the laundry room at the opposite end of the house from my tank (probably 50ft of tubing or more). Do you see issues with this... also are there any reasons why I couldn't add RI later (if desired) vs. going with an RO/DI system up front.
