RO help!!~!

[Mike31154]

Yea, I dunno, you got me there. I guess comparing the refractometer, an analog scale, to the digital TDS meter is not a good example. I'm on an anolog kick, thinking of the old multimeter where you can actually get the indicator to read below zero when you're adjusting it to read resistance.

[Buckeye Hydro]

Here are some thoughts:

Where is your system manufacturer (aqua-safe) and your system vendor (usa shower) in this process of troubleshooting your system? I don't see them on either of the two threads you started on this topic.

You now have two 1 mic sediment filters as stages 1 and 2. Again, this is an odd configuration. IF you have heavy sediment loads (remember that high TDS feedwater DOES NOT mean you have high sediment loads), you could place a 5 micron sediment filter in stage 1, and a 1 micron sed filt in stage 2.

Remember that prefilters (all the sediment filters and carbon before the membrane) DO NOT remove TDS. That's done by the RO membrane and the DI resin.

Do you have chloramines in your tap water? If not, get the CGAC out of the system.

Let me know the specs of your carbon block. 20 micron? 0.6 micron?

Having a sediment filter after the carbon block is an odd configuration. What is the micron rating of this sediment filter?

If I understand correctly you have two 75 gpd membranes, but you've said you have 2 100 gpd restrictors. If this is true you should remove your current restrictors and install the correct restrictors.

You keep mentioning "RO beads." Do you mean "DI beads?" We have seen lots of customers who get new DI resin from ebay outfits like aquasafe only to have the new DI resin be bad right out of the box.

You said you have a taste and odor filter after the DI stage. A taste and odor filter is gac, and should never be placed after a DI stage. The water is as clean as your system can make it after the DI. Why add contaminants back in by running it through GAC?

If I understand your TDS readings you have:
Feedwater: 900 ppm
RO water: 25 ppm
DI water: 25 ppm

25 ppm out of your membranes is VERY good considering how bad your feedwater is.

25 out of your DI means your DI isn't doing its job. Replace the resin. Remember what I said above that new resin can be bad right out of the box.

You need to install a pressure gague kit in the tube after the last prefilter and before the membrane(s). You want to read the pressure that is actually reaching the membranes. Given that you have 5 prefilters (I'd change this - see above), it very easily could be that you have much less pressure at the membrane thatn you have in the line feeding the system.

I looking in your other thread and you have your DI set up oddly. You have moved it from horizontal to vertical - that's a good thing. But you need bottom-up flow. Looks like you have top-down flow.

Someone else said it above - you are asking your DI resin to do a ton of work with that high TDS coming out of your RO, and 150 gpd of flow, and yet you have a small DI housing. Think about getting a full size, refillable, vertical DI resin stage - or better yet, think about a double DI.

I'd have to see some additional pictures to see if your system is plumbed correctly. If you have the product water (the "permeate" or RO water) from the first membrane feeding the second membrane - that is a problem considering what else you've told us. Given your high TDS feedwater, I WOULD NOT suggest a more typical set up for plumbing membranes in series - where the waste water from the first feeds the second membrane. If you are certain you need the volume of flow two membranes will produce, then you'll need to plumb them in parallel.

You mentioned you have tou DI water running to a faucet. Really? If so, that's a no-no. Don't drink that water. You want to drink RO water. You should not expose a metal faucet to DI water.

Here's some general info re TDS readings:
In this hobby we measure Total Dissolved Solids in parts per million, or "ppm." We often try to measure TDS down near 0 ppm. Because this TDS level is so low, we have to keep in mind the sensitivity of the meter used to measure it, and the technique used to measure the tds.

Nearly any contamination in the sample container will cause an erroneous TDS measurement. Some plastic containers are difficult to get absolutely clean, and although they appear clean, they are not. An easy standard approach is to use a drinking glass as a sample container - use one right out of the dishwasher. Obviously, keep your fingers away from the inside surface of the glass.

Calibrate your meter. Use a calibration fluid generally in the range of the tds measurements you'll be taking. Some meters require a specific tds calibration fluid (e.g., 800 ppm), regardless of the tds levels in your samples.

Be careful with how you take your samples. Let's say you intend to measure the TDS in your 1) DI water, 2) RO water, and 3) tap water. Start with the cleanest of the three - the DI water. After letting the system run for a sufficient period of time that you are sure the tds levels have stabilized (to assure you are not measuring tds creep water), rinse the sample container two or three times with the water you intend to sample, and then fill the sample container with sufficient DI water to take a reading.

Now on to the RO water. The water we are interested in here is the permeate – i.e., the water that has been purified by the RO membrane – not the waste water. Make sure you understand which is which before taking the sample. Most RODI systems other than Buckeye Systems are not plumbed to facilitate taking a sample of the permeate. If that is the case, you’ll need to unhook some tubing – likely where the tubing attaches to the “in” port on the DI housing in order to take this sample. This is inconvenient for many people, and we find that people never do it. They report only the tap water TDS and the DI water TDS. Contact Buckeye if you need guidance regarding installing a couple of extra fittings and tubing to facilitate measuring the TDS of the RO water (permeate). When you take the sample, follow the same procedure described above – use a clean sample container, assure you are not measuring TDS creep water, rinse with the permeate several times before taking the sample, and use a calibrated meter.

Use the same approach to collect and measure your tap water as well.


Russ @
Buckeye Field Supply

[ItsMee]

Thank you very much Buckeye. That's about as detailed as it gets and is exactly what I needed. Thanks again for typing all that out. I

have some re-adjusting to do, which includes calling aqusafe about my beads, getting a new bigger DI housing or two, removing both add-on cartridges (hey, can I use standrad 10 inch cartridges as DI housings?), setting up the prefilters to be 1micron-catalyctic carbon (yes, they use chloramines), "carbon block"? - doesn't say what micron. And then to a single 100GPD membrane with it's matching 100GPD restrictor. And plumbing it so that it does not come out of the faucet (even though I like thet taste of it) because it is not good to touch metal.

[Buckeye Hydro]

The trick to the faucet is that you want to deliver RO water to the faucet, but use DI water for your tank.

For instance, our ree/residential systems are plumbed like that - they send RO water to a pressurized storage tank, and then on to a faucet; while other RO water goes on to the DI stage. If you want to see how that is plumbed, all our instruction sets are posted on the website.

RE your DI stages - YES - use some of the 10" housings that you already have. You'll just need a refillable DI cartridge to put inside the housing. Plumb the DI housings in series - one after the other. Ideally you'd have a way to measure the TDS of your 1) tap water, 2) ro water, 3) water after first DI, and 4) water after second DI.

RE your carbon block:

For purposes of the marine aquarium hobby, consider two items: pore size and chlorine capacity. The smaller the pore size, the greater protection the block offers your RO membrane. Carbon block cartridges with a pore size of 1 micron to 10 microns are common in the hobby. Carbon blocks with smaller pore sizes serve as a backup filter to catch those few particles that make it past the sediment filter. For example, the Matrikx+1 Chlorine Guzzler has a nominal rating or 0.6 microns, and an absolute rating of 2 microns. You'll also see it rated at a 1 micron (the 0.6 microns rounded off). Because your sediment cartridge should be in line ahead of the carbon block, the primary purpose of the carbon cartridge is to remove VOCs - volatile organic compounds, and more specifically in filtration of tap water, what we really want it to do is remove chlorine.

Just how much chlorine will a carbon cartridge remove? The cartridges are rated in terms of chlorine capacity. The Matrikx+1 for example will remove >90% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons. Steer away from buying carbon blocks with unknown specs - you can rest assured if the specs were good, the manufacturer and vendor would tell you.

Russ

[ItsMee]

Cool. To add to my shopping cart: 2 refillable DI cartridges (with these 2 catridges, and the one I already have I will have 3, or should I not use the smaller one I am now using?), Lots of DI resin from bulkreefsupply, and 1 micron rated blocks. Man I got ripped off from that other place-what a complete waste.

[Buckeye Hydro]

I think two full size refillable vertical DI housings would be the way to go, but it you want to continue using the one you have just make sure it is vertical with bottom up flow.

If you have some DI resin already, make sure it is in a vapor barrier bag, and kept in the dark.

Russ