Rodi dissicussion

[thegoatc]

ok so first i cant spell so dont hate second does anyone own a general water rodi filter from filterdirect if so do you have the pressure tank that comes with some of them. third do any of you use the pressure tank to fill your reeftank.
just wanted some info on it because i have herd of the pressure tanks have an antifungal agent in them which can kill a reef tank in a quick hurry thanks and hope to hear form some of you soon.
eric

 

[Roly]

I have the "General". I dont use the tank. However, I dont have it connected all the time. I just take it out when I need water. I make huge amounts of water and disconnect it. I bought the fauset adapter along with it. I have heard that disconneting iot isnt good but I always test my water after a while and everything always comes out perfect.

 

[thegoatc]

thanks but just wondering if anyone has used the the tank with good results or bad results thanks again
eric

 

[twilliard]

I have been using tanks now for 3 years. No adverse effects.

 

[thegoatc]

thanks twillard may i ask waht brand of pressure tank you are you useing

 

[crazydante23]

They sell these rodi units on ebay, Are they good thegoatc?

 

[thegoatc]

they are very decent units they come with good hosings the only thing i would change is the di hosing is not the easiest to seal if you get just one little pice of di resin in it it will leak but this is only something you have to worry about like everysix months or one year any way but the tds is zero all the time and i have a friend who uses one and it works great for him.
eric

 

[crazydante23]

Thanks, Im thinking of buying one for drinking and reef water. Im getting tired of lugging around 8 bottles of water around every week.

 

[DonW]

Thanks, Im thinking of buying one for drinking and reef water. Im getting tired of lugging around 8 bottles of water around every week.

They are great for the money spent. The housings are as good as or better than the big names like SP........ The horizontal di housing is pretty much worthless unless you have very low tds to begin with, they channel and pulverize the resin. The stock filter are good along with the membrane and are easily upgraded when the time comes to replace them.

Don

 

[crazydante23]

what do u think about this one Don?
http://cgi.ebay.com/ws/eBayISAPI.dl...MEWA:IT&viewitem=&item=120115750342&rd=1&rd=1

 

[thegoatc]

the horzontal di is not that bad and the tds should be very low going into the di any way if it is above 4or5 you probably need to replace your membrane

 

[thegoatc]

that is the one i just bought and it taks my 300 tds tap water to zero
eric

 

[DonW]

what do u think about this one Don?
http://cgi.ebay.com/ws/eBayISAPI.dl...MEWA:IT&viewitem=&item=120115750342&rd=1&rd=1

Thats the one I started with. I never used the tank but it will be fine. I would loose the di and get a vertical unit bottom line the di channels.

 

[crazydante23]

The goat, did you buy from ebay if so how long did shipping take? Im guessing your satified with the water quality. Do u use it for drinking water to?

DonW, what is that controller thing u have on your unit? And where did you purchase the verticle di line?

 

[DonW]

the horzontal di is not that bad and the tds should be very low going into the di any way if it is above 4or5 you probably need to replace your membrane

Not really. If you have 300 tds incomming in a perfect world at 98% rejection you would have around 6 leaving the membrane. Since the water temp is usually to low to get 98%, the tds will be even higher adding to the fact that the stock membranes are not 98% membranes the tds should be even higher.
Now if the tds was low like mine 30 on the incomming by the time it goes through my second mebrane its not even measurable in terms of tds unless you measure actual conductivity. I go through 1 vertical cartrige every 4 months, which holds almost double the resin of a horizontal cartrige.

Don

 

[DonW]

The goat, did you buy from ebay if so how long did shipping take? Im guessing your satified with the water quality. Do u use it for drinking water to?

DonW, what is that controller thing u have on your unit? And where did you purchase the verticle di line?

When I got mine they were $69.95 but back then their service was fine.

I get all my filter needs from www.thefilterguys.biz
(edit) The "controller" is a TDS meter.

Don

 

[thegoatc]

shipping was about 4 days and all around good stuff but donw really know what he is talking about there are pros and cons.
eric

 

[Reefdaddy1]

Don I assume you were talking about Spectrapure in your statement about the housing. If so I would have to beg to differ. The units they provide can clear a TDS reading unlike any you have seen. Currently my water is about 800 PPM on a TDS meter. Will go up to 1280 this summer. Show me any unit on the market that can get that TDS down to about 5. I have owned many types of DI, just recently bought a spectrapure. WOW what difference.

 

[DonW]

Don I assume you were talking about Spectrapure in your statement about the housing. If so I would have to beg to differ. The units they provide can clear a TDS reading unlike any you have seen. Currently my water is about 800 PPM on a TDS meter. Will go up to 1280 this summer. Show me any unit on the market that can get that TDS down to about 5. I have owned many types of DI, just recently bought a spectrapure. WOW what difference.

First go back and read my statement it was regarding housing quality.
Now if you want to discuss membranes we can do just that. But first we have to talk about tds meter accuracy and touting numbers. Unless you or any of us are useing lab equipment numbers are just a grossly exagerated guidline when it comes to tds.
Now lets look at some numbers. At at tds of 800 in a perfect world, yes even your spectrapure will only have 98% rejection rate. That leaves us with a tds of about 16 comming out of the membrane. The di resin being in good in a decent horizontal cartrige will easilly bring that down to a reading of 0 on a hobbiest tds meter no mater who's sticker is stuck on the rodi unit.
Now since this is not a perfect world and even with a spectrapure unit there guidlines for achieving 98%. Water pressure and temperature are just two. Most of us have plenty of pressure, but if not you can count on the fact that no matter what brand you have your not going to get 98%. Most of us do NOT have a water temp high enough to get 98%, unless of course you live in the desert and most of the country does not. So 98% is nearly impossible number to achieve no mater what brand you have.
Brand name do NOT filter water, filters(not housings) filter water. That being said, a water general unt can be made to filter just as good as a spectrapure just by upgrading the insides when the time comes. Changing the membrane to the same dowfilmtec and buying good lower micron pre filters is a good start. As I stated changing to a vertical di with good resin is key to getting real low numbers even with very high tds. Now go out to dinner with all the money saved and you still have some extra money for whatever.

Don

 

[thegoatc]

i love when discussions are informative and when real numbers and choice brands are used this really helps everyone who is still fairly new and would like to learn more with out spending the money to find out the hard way. thanks
eric

oh and has anyone else used pressure tanks to do top offs with just would like some more responces on that matter.