RO unit troubleshooting questions

[schiller]

First, I would like to start off by appologizing for the long post. I peruse message boards almost daily, I just don't contribute much, so be kind, but I was wondering if any of you experts (

) could lend me a hand with an issue I have been having.
I live in a rural area, using well water, and to put it bluntly - My water here is bad. So bad there are warnings in the paper not to consume (hehe). This is mainly due to the nitrate concentration.
SO - I have been having someone run maintenance on a reverse osmosis system even before I entered into this saltwater hobby so that we have something to drink. And the blessing of it is if I never stumbled into the hobby - or been so anal about checking water parameters - I would still be unaware, but the RO unit does not remove our nitrates. It lowers the TDI an insane amount (I don't have a meter on hand, but I have had it checked and will elaborate below. In short TDI is over 1000 at the well, 120 at unit without increased pressure, and 40-50 with pressure), but nitrates keep hovering. So I alerted the company and have been working with them to resolve the issue, but nothing is helping and I am buying bottled water, while paying for this units operation for 3/4 of a year now and it is time to find another avenue.
So here is how it went down:
Used the unit initially: I thought it was clean water, but I couldn't figure out why the tank's nitrates were high. Well it was because I was pumping more nitrates into the system with each water change I attempted and was making the problem worse. So I tested the RO unit and nitrates were off the chart. (started buying RO/DI bottled water for the tank at this point, tank water isn't an issue, just my home.)
Next step: changed filters, still bad, moving on..
Next: added another stage (the company claims it is like a 5 stage because some filter is supposedly combined, I dunno...but from what I have seen for sale all 5 stages are ro/DI and I am not sure that is our case, so whatever, give them the benefit of the doubt, or call it a 4...I call it a 4, but regardless...). There was still no change. TDI are over 1000 without filter and around 120 with filter. Nitrates remain high.
So next: We bumped up the house well pressure..no change....bought something to bump up the pressure going through the unit (might be 80lbs?? now? there isn't a gauge for me to tell you exactly). I was informed that the only difference at this point from where I get my water (a BYOB windmill thing) and mine was that theirs was set at 150lbs pressure and this should take care of the problem. Checked TDI and they were reduced to 40-50. Well it did not cange the nitrates.
NEXT STEP: by this time I am tired of hauling water from the nearest town 30 minutes away...and we add a nitrate filter. YAY!! the unit now produces 0 nitrate water!! but it tastes like ass.
ok...wait another few months and now we have added another carbon filter post the nitrate filter. It is a little better in taste, levels holding good.... I'm going along all happy and EEK! There creeps those nitrates in again! In less than a month I have gone from 0 nitrates to 20... in just over a month we are at 40 nitrates..
br />Now these buggers are $$$, plus I pay a monthly rental fee on equipment. Does everyone replace their filters once a month? really? with increased pressure and all??
Ok, so I have been told that every working part of the machine has been replaced and is new at this point. That every supplier/producer/whatever contact has been contacted and probed for information and no one will recognize the problem and it shouldn't be happening, and it is just me. So I take a little sample from other people with these units and theirs is high too. Allbeit not off the charts as I started, but still over the limit for consumption (I think that is 10, at least here..isn't it?). Given, I test with API, not the best, not the most reliable, and the version of test that is for total nitrate (4.4X higher) when compared to the local lab (who yes I sent off to and has confirmed the results) that tests for nitrate-nitrogen. However, that still places me over the accepted limit in two months even with their test.
So, after the rant, here is the point, or question I should say:
Does everyone/has anyone experienced this problem? How often is everyone replacing their additional nitrate specific filter (if they have one). Does this sound insane to anyone else? What is and how can I fix the problem here? And lastly - if I purchase an RO/DI unit from the bulk guys would I still be having these issues/what pieces do I need to include in the purchase to ensure I won't continue to have these issues? I am OBVIOUSLY not understanding something.
So I can have water for less than a month to drink, but this is not good enough for my fish. Yep, they are spoiled. Them and my twin toddler girls...they all get bottled from town and mama gets the junk from the well..
Here is to my constant level of confusion

 

[mr. limpid]

Buy a Aqua pure filter and use it on the water change water B4 you do a water change. If I were you I would buy a second one for DT.

 

[snakeblitz33]

Sorry your having so many problems.
I know a thing or two about RO/DI filters, maybe I can help you out.
City water usually runs between 100 and 200 TDS... (TDS is Total Dissolved Solids) which between 0 and 5 are ok for a TDS reading from RO/DI water.
They are probably saying that your unit is five stage, because they count the RO membrane itself. Membranes need to be flushed on a monthly, if not weekly basis... Ammonia and chlorine really degrades RO Membranes - so carbon blocks are a must. Usually an RO unit starts off with a 10 micron filter, and then a 5 micron carbon block and then a 1 micron carbon block. Then it enters the RO membrane - which squeezes water through the membrane (your RO Unit should have a max PSI between 60 and 75,... check before you keep it at 80psi.)
Typically the last stage is a DI membrane - or DeIonized -... it uses a cation/anion resin which removes ions from the water that is leftover from the RO membrane... which is usually where most PO4 and NO3 are mopped up.
Adding a DeIonizing unit probably will more than likely help, if you haven't already.
Something that might be more commercially viable for you is a "water softner" which is a whole house water purifier, basically. You could run water through it for your whole house and run it's water through your RO/DI Unit.
At a TDS of 20, your nitrates shouldn't honestly be that high. I think your getting a false reading from your API test kits. Check to see when they expired.
Yes, I do recommend buying your own RO/DI filter, and yes, you may come across the same problems, but at least you will have your own filter!
If you persistently have problems with your nitrate levels in your display tank, try building an algae scrubber. It will/should be able to handle the excessive amounts of nitrate coming from your RO/DI as well as the fish waste - if sized and built properly using a decent lighting system.
Good luck!

 

[schiller]

Thanks for the answer! And yes, unfortunately, it is that high (as per checked at the professional lab), and therefore it is confusing everyone I speak to. However, it is RO, and does not have the DI. So, as you mentioned, it seems the fix for being able to use it for the tank would be to add the DI (which they were avoiding since we use it for drinking as well). I think I will contact them to add it, and assuming it cures the issue, I will purchase a unit. I just didn't want to spend the money and not know what it took to fix the issue. I bet it could be plummed to be turned on just for the water changes?
On the other hand:
I know that the softener would reduce the TDI, but would it also reduce the nitrates, or would they continue to slip through that stage? I am curious to know if adding one and reducing those TDI before it hits the unit's filtration would allow my nitrate filter to last longer (which is my immediate goal atm). I've been wanting one for a while, but as far as personal use we are mostly wanting the nitrates out for safe consumption. As I have said, we saw the nitrates and have been buying RODI for the tank ever since (I'd say a good 9 months). If so, it seems this would be a more appropriate route for achieving water for all the household purposes...
Thanks for the advice! So much nicer to get advice in a few days, rather than months to a year from the company...

 

[schiller]

as far as the test kit being out of date, I thought of that at the beginnig when I was shocked to see the result...bought three different test kits, all in date, and had it professionally checked at a lab.

 

[snakeblitz33]

I'm not saying that a DI unit will correct the problem - I'm saying that it may definitely help take care of lowering your TDS coming out of your RO membrane. Over time, you can visually see your DI resin be exhausted, and TDS creeping up will let you know to replace it. I've never really heard of a nitrate filter, and I don't know anyone in the hobby that is currently using one on their freshwater purification system.
Please refer to Total Dissolved Solids as TDS, not TDI. I have no idea what TDI means, but if you are using a TDS meter, you are measuring Total Dissolved Solids - I have no idea what an "I" would stand for in your acronym. I'm a stickler for nomenclature - when trying to talk about an idea or a concept, it's best to use the same terminology and the same definitions so that we can be on the same page, yah know?
What a water softner will do is remove calcium, magnesium and heavy metals from the water, thereby making it soft... soft water systems increase the longevity of your appliances - like your washer and dishwasher and hot water heater. It keeps lime scale from building up. Your RO Unit filters, such as the micron fiber filters remove bacteria, fungus, dirt, debris, and sludge from your water. The carbon block filter should remove many toxins and chemicals that may be present - but it does not remove fluorine to my knowledge. The RO membrane forces some water through the membrane - and spits out waste water - water that can not be purified, that contains contaminants. A DI resin will remove additional ions from the water, including both nitrates and phosphates and other ions, such as calcium ions and magnesium ions that may have escaped through a compromised membrane. DI resins are inexpensive - roughly $20 and they are refillable. They in general last about three to six months, depending on how much water you are using.
If you are considering a water softener, hook it up to your whole house water - so that it will benefit your shower, dishwasher, washer and boiler (Hot water heater)... and then after the water softner, add your RO unit. After your RO Unit, run it through a DI resin. This should be absolutely pure water. If you are having trouble with the taste of the water coming out of the unit, they make an in-line "filter" that adds ions and minerals back into the water to make it taste better - but remember, that should be a T-off your pure water line - so that you don't go through the trouble of getting absolutely pure water and then adding ions back to it. lol
If your micron fiber filters are getting way to brown too quick, a pre-filter called "Big Blue" is a great addition to a whole house filtration system.
I know when I start building my house I will be on well water myself, and will be adding a water softener for the household appliances and showers... and a big blue to my kitchen sink and a pre-filter for my RO/DI unit. I've had enough biology/chemistry education in college to know better than to drink the crap that comes out of the tap in my city.

 

[snakeblitz33]

By the way, here are a few other tips for your unit...
1. the waste water can be collected and used for your gardens, or even outdoor ponds or flushing sewage systems. Waste water conservation is very important - and using it wisely can help save you some money, and help the environment. If you haven't done it already, grey-water collection is a great way to save on your water bill, by recycling water from kitchen sinks (and your RO waste water) to flush toilets and water your gardens.
2. Replace your carbon block filter once every three months, regardless if your TDS is still 0 or not. The reason the carbon block filter has to be replaced is that chlorine, chloramines, and other chemicals that are in your water (I don't honestly know much about wells, other then they are like underground springs) like pesticides and herbicides need to be completely removed from the water before entering into your RO membrane. If chemicals are allowed to reach the RO membrane, the membrane is compromised and will, no matter what, keep spitting out a high TDS. RO membranes last anywhere from 1-5 years if taken care of properly and never allowed to dry out.
3. Make sure your TDS meter is calibrated. Buy some distilled water - something you know should have a TDS reading of 0 and test it. Then test the TDS of your RO/DI water. If your distilled water has a high TDS reading, your meter could be inaccurate.
4. In-line TDS meters aren't always the most accurate things. Read your manual and see how you can calibrate it as well.
5. If you don't already have one, I highly suggest getting a pressure gauge that goes on the line before it reaches your RO/DI unit. Some RO units function only at certain PSI - and increasing the PSI of your line doesn't necessarily mean that it will function any better. It could in fact damage the seals of the unit.