New RO system only giving me 8ppm??

[trevorspencer94]

Hi all, I bought a 75gpd 4 stage reverse osmosis water system online, and since it was brand new, I let it run all day for a couple days, this lowered my tap water from 195ppm to 8 ppm, but I don't understand really why it isn't going down closer to 0. The sink has pretty high pressure (haven't measured it, but it's more powerful than most house faucets I have ever seen), I'm using it on cold water only, I'm just concerned maybe this is the best it's going to get? And is 8ppm good enough to use to mix my water and for top offs? What I was buying from the store originally was 1ppm. But I bought this unit to save me money in the long run. Please help!

 

[AZDesertRat]

You state is is an RO system and not an RO/DI system. If that is the case a TDS of 8 would be just slightly less than normal for RO only. RO does 90-98% of the treatment, it takes DI to polish off that last 2-10% and get it to 0 TDS.
To calculate your rejection rate or removal efficiency take your tap TDS, subtract the RO TDS, divide that number by the original tap TDS and finally multiply the result by 100. Using your numbers, 195-8= 187, 187/195= .9589, .9589x100= 95.89 or basically 96% rejection rate or TDS removal.

If it is in fact a RO/DI system then you need 3 TDS numbers to troubleshoot it, tap TDS, RO only TDS before the DI and final RO/DI TDS. Those are just for basic troubleshooting, eventually to really understand your system you need to know the water pressure, water temperature, calcium carbonate hardness and your exact measured waste ratio.
It also helps others to help you if they know what filters, RO membrane and DI resin you have and whether the DI is mounted vertically or horizontally. DI resin also needs to be fresh and unopened, it has a relatively short shelf life, especially if it has been opened or allowed to dry out.

 

[trevorspencer94]

Thanks for the info! This is my first system, only been into reefing for 3 months! It's vertically mounted (each of the 4 tubes is positioned vertically). Is 8 tds going to cause me problems if I use it for my water??

 

[AZDesertRat]

I wouldn't use it myself but I'm anal about water quality. So, am I safe in assuming it is an RO only system and not RO/DI? I would pick up an add on DI filter if that is the case so you can get that to 0 TDS.
Normally a 4 stage RO system would have 3 vertical filters on the bottom and a horizontal RO membrane on the top? What did you buy?

 

[ngvu1]

Do we need to rinse the carbon block on brand new RO/DI systems? I always rinse the carbon blocks, bought separately, and they have always pushed out black, very black water for the first few gallons.....I wonder if we don't rinse the media first and just plug it in and use then all the junk will end up in the membrane killing the membrane guy short...! Just a thought.

A buddy of mine bought a used RO/DI system but in good condition (good membrane, and DI canister). He replaced the carbon block and flush it without taking the membrane offline....both membrane and DI went bad after 20 gallons or so of water..

 

[AZDesertRat]

Search my username and flushing or disinfection and it will bring up a very detailed flushing sequence to prevent exactly what you are talking about. Yes you should flush each filter, membrane and DI sequentially.

 

[bobman]

I dont rinse it in the sink persay but when I change my filters I just disconnect the ro memberane and let that run till its clear. Not sure if its the best way but thats what I do

 

[ngvu1]

Well, I do that too. maybe "rinse" is not the right word but flush rather....!

I dont rinse it in the sink persay but when I change my filters I just disconnect the ro memberane and let that run till its clear. Not sure if its the best way but thats what I do

 

[AZDesertRat]

https://www.reef2reef.com/threads/did-i-ruin-my-filter.117823/#post-1324928

This is an old post and has more detail than you may need as it goes into disinfection and RO membrane replacement too.

 

[trevorspencer94]

It's one of the eBay portable 75gpd units. Went cheap cause I didn't wanna spend as much on the ro unit as I have into my whole set up lol, but yeah I have heard of people buying a di for $35 or whatever and adding them to it. I could do that. Yes it's just RO, I thought I said 4 stage RO system in the original post... Will have to go back and check, this unit has all the canisters vertical, 2 on one side of the resin and 1 on the other side of it. I flushed it and all that black crap from carbon came out for a few gallons before I added the resin filter and started running it. Made sure it was clear and then continued to run it longer after before adding the resin. I guess I will just order the extra di step to add to it

 

[trevorspencer94]

Just ordered the di canister with resin already in it from BRS for $39.99 shipped. [emoji106] I'm paranoid about what that extra 8 ppm could be lol. Rather do it right and bite the extra $40 and have better water anyways than potentially lose hundreds of dollars of livestock.

 

[AZDesertRat]

Going cheap is never the way to go with RO/DI. You could have had one of the best reef quality RO/DI systems on the planet for around $125 and it would end up costing you much less than the ebay system in its first year of operation due it better filters, much more efficient RO membrane and fresh reef quality DI resin. I really hate to see people waste money on ebay quality filters as it almost always ends up biting them. You said it yourself in your last sentence, "potentially lose hundreds of dollars of livestock". It does not pay to skimp when it comes to water quality. There really is a big difference between ebay systems and those sold by popular vendors such as Spectrapure, Buckeye Hydro, AWI, PurelyH2o and a few others. I do not include BRS in this list as they are average at best and the others go above that.

 

[Robert59]

Hello gents,I am looking to purchase an ro/di system for under my sink I'm wondering does it come with hook up to splice into the cold water supply I am new at this my first saltwater tank thanks

 

[AZDesertRat]

Some come with self piercing needle valves but I would recommend either a feed water adapter valve for under sink installations or a garden hose style wye adapter for hooking up to the washing machine cold water supply instead.

 

[Robert59]

Hmmmm never thought of washing machine great idea I'm in an anpartment I have to see if I have enough room I like that

 

[Robert59]

Which one you recommend I have not purchase any thing yet trying to get inputifyou can send me a link would be appreciated

 

[AZDesertRat]

This RO/DI which is on sale at 15% off:
http://spectrapure.com/Refurbished-90-GPD-RODI-System

And a feed water adapter such as this which fits on the cold water supply valve under a sink:
http://spectrapure.com/PARTS-SUPPLI...pter-1-2in-male-x-1-2in-female-x-1-4in-tubing


or like this if you have a washing machine:
http://www.amazon.com/Orbit-58248-Y-Connector-Shut-Off-Valves/dp/B000YDVRH8

 

[Robert59]

I want to thank you for your help and knowledge I ordered it both of them

 

[Robert59]

I'm also looking to find a bigger sump is there a site which you recommend I have a 44 gal pentagon with a cabinet looking to get one mine is small

 

[AZDesertRat]

I use a 30 gallon long AGA aquarium with homemade baffles for my sump. Glass tanks make great sumps if you can find one with the dimensions to fit under your stand. Rubbermaid totes make pretty good sumps also. Any LFS should be able to have a custom sump made to your dimensions too but it may be a little expensive compared to building your own.