RO/DI unit what one

[Jody]

Hi all

looking to buy a RO/DI unit just not sure whats best for me

I have a water softener installed because I have super hard water very high iron and bunch other stuff I have a sediment filter installed before my softener

Water parameters out of my tap now are

GH 60 ppm
KH 100 ppm
PH 8.4

So I cant get nothing to expensive I was looking at this one

http://www.petsandponds.com/en/aquarium-supplies/c238376/p16738892.html

also this one but not sure on how to build it anyone out there that can help ? http://www.bulkreefsupply.com/store/build-your-own-ro-system.html

Or any other system out there that might match my needs

Tanks I have are 46 gal Fish/reef, 20 Gal frag , 10 Gal fish only and 2 X 33 gal fresh water This RO/DI needs to be somewhat portable so i can use it then put it away kinda thing. Also the unit needs to have shipping to Canada. Last question do i need the De ionization part of the RO unit ?

Any help would be great Thanks all

Darn can someone put this in DYI/Equipment

 

[Ace25]

Ok, first thing to think about, the water softener. I believe it is a "no-no" to put an RO/DI unit after a water softener. The reason why escapes me at the moment but I remember reading it wasn't supposed to be done and there was a valid reason, hopefully someone that remembers can chime in and say why.

On to which units.. well, IMO they all do the same thing, it is the filters in the units that make or break it and those are universal/interchangable so even the cheapest RO/DI unit can work as good as the best one if the right filters are put in it.

So the 2 units I think are probably the best price/performance would be:
http://www.bulkreefsupply.com/store/75-gpd-ro-di-5-stage-standard-system.html
and
http://www.thefilterguys.biz/ro_di_systems.htm ($160.00 - OCEAN WAVE+ FIVE STAGE 75 GPD RO/DI)

Pretty much the same thing.. and even the same price.

 

[Jody]

Thanks Ace

But from what i can find it says having a water softener before the RO can help prolong the life of the membrane and it is suggested that a water softener be fitted before a RO unit but its just what i found On line so who knows

Thanks for your reply

Still need this post moved :dance2:

 

[Ace25]

I am thinking it has something to do with the hardness of the water, it drops it too much and makes it not as ideal for a SW tank. Just what is coming to mind.. I could be completely wrong though so take what I am saying with a very big grain of salt.

Edit:
This is talking about FW fish.. maybe it is more of a concern with an LPS/SPS type of reef tank and not as big of a deal for a FOWLR tank. I still would prefer to not use a softener if I had the option.
http://fins.actwin.com/mirror/begin-chem.html

Some fish (e.g., discus, cardinal tetras, etc.) prefer soft water. Although they can survive in harder water, they are unlikely to breed in it. Thus, you may feel compelled to soften your water despite the hassle involved in doing so.
Typical home water softeners soften water using a technique known as ``ion exchange''. That is, they remove calcium and magnesium ions by replacing them with sodium ions. Although this does technically make water softer, most fish won't notice the difference. That is, fish that prefer soft water don't like sodium either, and for them such water softeners don't help at all. Thus, home water softeners are not an appropriate way to soften water for aquarium use.

Better link to wetwebmedia, first question.
http://www.wetwebmedia.com/h20tapfaqs.htm

 

[Jody]

Thanks and that is the article i read at tipped the scales for me in wanting a RO/DI unit

and just found this

Pre-treatment for the RO unit, as needed. The reverse osmosis unit itself usually has only a small sediment prefilter. For some situations, where the water is good except for a high amount of sodium, for example, no additional pretreatment is needed. For most well water, however, the RO unit will need to be protected from sediment, iron, manganese, or hardness. This may require the use of a sediment filter, a water softener, an iron filter, or a sequestering additive (such a polyphosphate injection) as a pretreatment to protect the RO unit. RO units used on city water (for water vending or final rinse car wash applications, for example) will require carbon or carbon/KDF prefiltration to protect the RO unit from chlorine or chloramines.

 

[Ace25]

The more I think about it the more I am left scratching my head as to the exact reason. Now I am going to be on google until I find the answer. lol. Just from reading, it seems like it really shouldn't matter with a softener if your using a RO/DI unit to get the water. The RO/DI is going to strip out most of the hardness anyway, it is the salt mix that adds everything back to the water. If you use a sodium softener it strips out calcium and magnesium, both helpful in SW tanks, but again, the salt mix adds all that back anyway so that should not be a concern.

 

[dbosman]

The more I think about it the more I am left scratching my head as to the exact reason.

The reason the RO filter should use water before the softener, is most use salt and leave a lot of sodium in the water. No point in wasting your RO membrane pulling that out when you can avoid it by taking water for the RO unit before the softener.

 

[Ace25]

Sweet! Thanks for clearing that up.. it was really bugging me. LOL.

 

[Jody]

Thanks

But Have have just read countless articles on this now, and best i can find is something like this , through Ion exchange the calcium and magnesium are both replaced with sodium Ions and RO membrains can handle/remove sodium much easier then Cal. mag. and prolong the life of the membrain and even the DI stage

TDS well remain the same or slightly higher. So I still don't know the answer to my question due to some conflicting answers.

Thanks again for your help

 

[Ace25]

Sounds like "which is the lesser of the 2 evils" type of thing if you have hard water. Either your RO/DI has to deal with excess calcium or excess salt in the water depending if you place it before or after a water softener.