Ro Di

[cabbagehead]

Greetings,
I am having a problem with my RO DI system. I recently have been getting 25ppm tds reading coming out of my unit. All of the filters are 3 months old or newer. I just changed the DI and switched to a vertical canister for DI instead of my two horizontal ones. I made this change thinking that I was developing water channeling in the two horizontal DI chambers and that this would fix my high tds reading.My TDS coming out of my faucet is 324. I have two questions:

1. Is 25 ppm TDS reading a bad thing?

2. What else could be causing the high TDS reading?


As always thanks for your input

JACK

[Rob]

the first question is going to be what is your water pressure going into the unit...
this is a common problem with units that are not working effectively, and will likely require you to get a pressure gauge if you dont have one.

[Astrivian]

This is a question i was about to ask rob. What is low pressure for an rodi? I happen to have the money for an rodi filter (i was looking at Pure Flo II at http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=12093&N=2004+113775). It comes with an optional pump, and i am curious if it is worth the extra $100.

[Rob]

is a hard call.
in order to know you need to know what your water pressure is..
i think anything under 40 PSI (IIRC) is too low and needs a booster..

[Astrivian]

Oh okay. I was thinking around 40 psi. I will have to check, perhaps buy a pressure gauge, check, then return it ;) . Just wanted to make sure. Also, does that unit look good? Nice price (about $110) for 25 gph. Yea, it's slow but i am patient, besides which i dont have any tanks over 50 gal (but i sure wish i did :) ).

[fat walrus]

Oh okay. I was thinking around 40 psi. I will have to check, perhaps buy a pressure gauge, check, then return it ;) .
i hope you are kidding. either buy it or don't.............do not abuse return privileges, pressure gauges are not cheap, probably because for each that is sold, it is used by 10 people one time and then returned. besides, being able to monitor and regulate your pressure will eventually save you a ton of money on your water bill and membrane replacements.

[JustDavidP]

Keep in mind that there are MANY variables that could kick in here... for instance..

My lovely town water department JUST flushed the fire hydrants in my neighborhood (we've had a LOT of rain and there was some "issue" with the water) TWO days after I replaced the filters on my RO/DI. THey successfully hosed up my filters in two days. They are so lodged with rust and other nasties that I went from "0" to "47" PPM TDS in TWO DAYS.

Also, your pressure WILL change with seasonal requirements and water drawdowns, pump station maintenance and other issues in the greater water supply. It's always god to have a booster pump to keep the pressure stability.

D

[Amphibious]

Any RO or RO/DI can benefit from a pressure pump but especially those on lower water pressure. Generally speaking if you are on city water your pressure should be between 60 and 80 psi which will be OK for the unit. Below 60 psi and your rejection rate (waste water to product) is too high. Spending $100 extra may seem like a waste of money but it is not. It will lower your rejection rate to near or maybe even 0. My place is on a well, my operating pressure is 40 psi my rejection rate is horrendous. However we recycle our waste water through our washing machine on the original fill and we siphon much into the lawn.

I just bought a pump from Bernie of TR fame and will use it with my new RO/DI unit to increase my product water.

Astrivian
Oh OK. I was thinking around 40 psi. I will have to check, perhaps buy a pressure gage, check, then return it ;) . Just wanted to make sure. Also, does that unit look good? Nice price (about $110) for 25 gph. Yea, it's slow but i am patient, besides which i don't have any tanks over 50 gal (but i sure wish i did

That is GPD, Gallons per day not per hour. If you can live with that fine but wanted to clarify the discrepancy. You may want to re-think that.

I would opt for a larger unit and would not spend that kind of money on an RO/DI unit. All of the units on the market are basically made from the same components provided by maybe a couple of manufacturers. Some companies, that buy components and assemble them, slap their label on them and sell them, charge way too much money. I would go to E-bay and do a search for Aqua Safe. I bought one of their RO/DI, 100 gal per day for under $100 bucks without the pump. (remember I just bought the pump from Bernie).

About buying a pressure gage, using it and returning it, would you really do that??? Please, re-think that one, too.

[Astrivian]

Lol! I was just kidding about using and returning the pressure gauge thing. No worries all :)

Also, ty for the price info. I will check ebay and see what i can find. I am pretty sure the water pressure here is good, so i am not to worried about that. I will watch the rejection rate and if it starts getting high, i will look into a pump and guage.

How many stages is enough? I see a lot of 2, 3, and 4's on the market. Is there a major difference between these? From what i gather, the 2 stages do not do the DI part of the equation, but i am not sure about 3 and 4.

thanks for the tips everyone!!

[Bernie]

I have to admit, I've been very happy with my aquasafe unit. Once I plumbed it correctly I was off to the races and have flooded my bathroom thrice now :doh: Good unit, and the folks at aquasafe are top notch. Check out eBay for them, or you can go directly to their site... something like aquasafecanada.com IIRC...

[Amphibious]

Lol! I was just kidding about using and returning the pressure gauge thing. No worries all :)

Also, ty for the price info. I will check ebay and see what i can find. I am pretty sure the water pressure here is good, so i am not to worried about that. I will watch the rejection rate and if it starts getting high, i will look into a pump and guage.

How many stages is enough? I see a lot of 2, 3, and 4's on the market. Is there a major difference between these? From what i gather, the 2 stages do not do the DI part of the equation, but i am not sure about 3 and 4.

thanks for the tips everyone!!I'm sure we all are a bit relieved that you were just kidding about the gage.

How pure do you want your product water and what is your budget? For my money, with the RO/DI I'd go 4.

I agree with bernie's statement about Aqua Safe. I think our fearless leader Rob has this unit, too.

[cabbagehead]

I am on city water and get a lot of flow out of my RO DI unit. I will be looking for a pressure gauge to see if I need a pump. What is puzzling is that for a couple of months my RO DI had 0 TDS. Thinking it was time to replace filters, I was dissapointed that this did not fix my problem. They have been working on the water system in my area recently so I wonder if that has anything to do with it.
Is it possible that 25ppm could be adding to my phosphate levels in my tank?

[Amphibious]

I am on city water and get a lot of flow out of my RO DI unit. I will be looking for a pressure gauge to see if I need a pump. What is puzzling is that for a couple of months my RO DI had 0 TDS. Thinking it was time to replace filters, I was dissapointed that this did not fix my problem. They have been working on the water system in my area recently so I wonder if that has anything to do with it.
Is it possible that 25ppm could be adding to my phosphate levels in my tank?I'm confused. At 0 TDS and a few months you don't need to change filter cartridges. So I'm assuming it jumped to 25 TDS after the water department serviced your area. It's possible but to be sure you'd need to find out if phosphate is part of the 25 TDS. With out knowing more it would be hard to pinpoint the source.

What is the level of phosphate in your aquarium?

[Astrivian]

How pure do you want your product water and what is your budget? For my money, with the RO/DI I'd go 4.

Ah yes, it comes down to the cash so frequently in this hobby. I have maybe $150 tops, so if i can find a 4 stage in that price area i will certainly grab it. If, however, i get this job i just interviewed for....well all kinds of fun stuff will change :)

[Astrivian]

quick question. Does this unit by Aqua safe look good for $89? Oh, and ty ty ty ty ty for the price info. That 25gpd was really expensive now that i am looking around TY TY TY TY!!!

http://cgi.ebay.com/AQUA-SAFE-100GPD-HOME-REVERSE-OSMOSIS-WATER-FILTER_W0QQitemZ180012591078QQihZ008QQcategoryZ206 84QQrdZ1QQcmdZViewItem

Oh, what is the metal jar on the side? Is that the fourth stage?

Trust me....soon i will stop bothering you all with these posts :) Ty for all your help everyone, it really saves me.

[Amphibious]

you're not bothering us. The unit you linked to is ONLY RO, not RO/DI. keep searching their goods for RO/DI for about the same price, maybe a bit more. The "jar" on the side is a storage/ pressure tank for drinking water at your sink. A nice ad on if you want really good water for cooking, drinking, making ice cubes for your cool aide. :rotfl:

Try this link - http://cgi.ebay.com/AQUA-SAFE-100GPD-MAXIMUS-REVERSE-OSMOSIS-WATER-FILTER_W0QQitemZ180012894205QQihZ008QQcategoryZ206 84QQrdZ1QQcmdZViewItem

[Rob]

Try this link - http://cgi.ebay.com/AQUA-SAFE-100GPD-MAXIMUS-REVERSE-OSMOSIS-WATER-FILTER_W0QQitemZ180012894205QQihZ008QQcategoryZ206 84QQrdZ1QQcmdZViewItem

yes, this is the exact unit i have... been very happy with it

[cabbagehead]

I don't know the exact day that work was being done on the water in my area. I do weekly water changes and always check the TDS. One week I had 0 TDS and the next it jumped anywhere from 19 to 25. I had replaced the carbon and micron filters three months ago. MY LFS had a good deal on a DOW membrane last month and I upgraded then. The DI resin was replaced when the carbon and micron filters were but after getting a 25ppm reading I switched to a vertical filter. This unit had prevoiusly performed perfectly except for a improper connection that was made by the manufacturer that had the drain RO water going to the DI filter instead of the drain. I fixed this problem and did not have a TDS problem until now. My micron filter is a little yellow after only three months of use. I would think that if the water coming in to the house was that bad that the TDS would be higher. The only thing I can think might have happen is some really bad water came through when I was not checking the TDS. I do usually make about 50 gallons a week when I do a water change so that I have some left over for top off. I am still researching the water pressure thing and will be trying to locate one locally to test before buying a booster. None of my corals seem afected by this and I have done three water changes with this water. I do have some minimal cyno in my fuge but it is already showing signs of regression and has not spread to the main tank. Macro algae is growing like crazy and my pod population is heavy.

Tank stats today
AM 0
PH 8.1
ALK 7
Cal 480
Nitrate 10
Phos 1.0

Thanks for all the responses I think I will be able to make a better decision when I get all of the information.
Jack