Carbon filter on well water for RO? Also a general setup question.

Swingline77 · Sep 19, 2018

It seems the main reason to use a carbon filter in an RO system is to remove chlorine. Since I don't have chlorides in my water, do I even need to use it?

Also, how much pressure is the water coming out of the RO system usually under? My display tank is in a different room than my water tank. I'm not sure how I'm going to set things up. There is a spigot inline between the well and the water tank. I'm thinking of hooking the RO system to this. Ideally, I'd have a waste water barrel right next to this, and then run a tiny tube from the system about 30' to a mixing barrel near the tank. If this wouldn't work, then I have to consider different setups.

By the way, the easiest way to do all this is for me to get an Aquatic Life 4-stage system. There are two issues, though. Reviewers stage leaking. Could this be easily solved with a few wraps of teflon tape?

The other issue is whether Aquatic Life uses standard size filters, or their own proprietary size. I can't tell. They certainly use their own modules, but I don't know if these modules contain standard size filters.

Thanks

redfishbluefish · Sep 19, 2018

If you're talking about an RO Buddy, they do not take conventional filter sizes. I'd recommend a "regular" RO unit that include DI.

And RO/DI removes more than chlorine. With well water, who knows what you have. A TDS meter will give you an idea of how "dirty" your water is. After passing through RO/DI, TDS should be zero.

Now dependent on the aquafer you're drawing from, it could have high carbon dioxide, which will burn through the DI resin real fast. This is a common problem with many aquafers in NJ. It can be fixed by first bubbling the water before going through the DI.

Finally pressure. You want, for the sake of picking numbers, a pressure of 70 - 90 psi of water pressure. If you pressure is too low, than you'll need a booster pump.

Hope this helps.

#reefsquad might have more to say.

Swingline77 · Sep 19, 2018

OK, thanks.

chipmunkofdoom2 · Sep 19, 2018

Good advice from @redfishbluefish. As to whether or not you need carbon blocks, I don't know. In general, residential RO systems use carbon blocks for chlorine/chloramine removal. I think you'd want some carbon to handle VOCs, which is the other thing carbon is supposed to do. But, nobody ever qualifies what a VOC is, of if they would be removed by the membrane if left untreated.

Russ @Buckeye Hydro might be able to comment. If he doesn't chime in here, feel free to call him. He is great at providing service here on the forums and helps all reefers whether they're his customers or not. He also has extensive experience in water treatment and actually knows what he's talking about. For these reasons, I would also strongly consider purchasing an RO filter from him if you haven't bought one yet.

Swingline77 · Sep 19, 2018

Great info. If I do need a booster, do you think that an Eheim 1262 would work, or do I need to get some sort of special "booster pump"?

redfishbluefish · Sep 19, 2018

No. The standard is the Aquatec 8800. There are knockoffs of this pump.

Bayareareefer18 · Sep 19, 2018

redfishbluefish said:
No. The standard is the Aquatec 8800. There are knockoffs of this pump.

My aquatec made a huge difference of performance of my RO system. I had about 42 psi at the membrane and after adding the booster it went to 82. Much faster water production and less waste.

One thing that turned me off about the ro buddy was the claim of 4:1 waste to production. You will be reusing your waste water so may not be a big deal. I went with a 5 stage 150 gpd brs unit.

Others have given good info about the carbon

I would have a water test performed so you know exactly what's in your water. Depending on your water params you could burn through some of the rodi components quickly.

Who knows your water could be really clean but would be good to know general params of the well water. You may even have record of this already

chipmunkofdoom2 · Sep 20, 2018

Bayareareefer18 said:
My aquatec made a huge difference of performance of my RO system. I had about 42 psi at the membrane and after adding the booster it went to 82. Much faster water production and less waste.

If you're getting less waste after adding a booster pump, you really should change your flow restrictor (or adjust it if it's the capilary style). If you get less waste with more pressure, that means you're forcing more water through the membrane.

I really wish we wouldn't call the waste water in RO systems "waste water." I think it gives people the impression that it's unnecessary or it something to be minimized if you can. This is absolutely not true. Waste water is necessary because of how RO membranes work. When you force water through a small film, the minerals get excluded. If you don't rinse them off the membrane film, they wild deposit and clog the pores, ruining the membrane. This is why RO systems produce waste water, and why they need a 4 to 1 ratio, to keep the membrane clean. Running less than a 4 : 1 waste to product ratio with TFC membranes will cause them to fail prematurely. How prematurely depends on how dirty your source water is. If you have low TDS, you can probably get away with < 4 : 1 for a very long time. But, there's no getting around waste water with RO systems.

It's also worth noting that tap water costs an average of about a third of a cent per gallon in the US. A 2 : 1 waste to product ratio will only save you just over $0.006 per gallon over a 4 : 1 ratio. Even if you need a hundred gallons of DI water a month, you're still only saving about $0.60 per month by using a 2 : 1 ratio. Considering that RO membranes cost upward of $35, it would take a lot of time to make your money back by saving on waste water.

Captain Quint · Sep 20, 2018

Chloramines will harm the membrane of a RODI unit.

Actually, ordinary carbon blocks will not remove chloramines. One would need cation and anion resins to remove chloramines.

If one does not have the cylinders for the resins to remove chloramines a capful of Prime will take care of the chloramines if you circulate it for a bit in the RODI fresh in your brute or whatever container one uses.

Swingline77 · Sep 20, 2018

It sounds like the advantage of a booster pump is increased production rate, not reduction of the "concentrate flow", right?

To comment on an above posting, the industry uses the term "concentrate flow" rather than "waste water". This isn't a case of euphemistic word twisting, it's actually far more accurate. For our purposes, we start with tap water. For other RO purposes, the starting water might be sewage, maple sap, etc.