Best RO/DI under sink

2580 Views 18 Replies 6 Participants Last post by sayn3ver, Mar 31, 2017

sfshrimp

Discussion Starter · Mar 19, 2017

What's the best RO/DI unit to buy for a smallish space under a sink? Would prefer to spend less than $150.00. There's now ammonia in the San Francisco tap water

. They are mixing municipal with ground water from Hetch Hetchey and the parameters are fluctuating. At my friend's house we couldn't figure out why his tank was not clearing the ammonia after cycling for two months, and then we tested the tap water - it registered .50 ppm.

Also - do you need to add more minerals to RO besides the KH/GH boosters? Would probably use salty shrimp to get a 6gh/3kh if I upgrade to RO.

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zackariah

· #2 · Mar 19, 2017

Air water ice is a great company. Excellent customer service. The owner spent 45min on the phone with me answering various questions. As far as adding minerals, you could also do a mix of tap and RO. Most people with nano shrimp tanks just add minerals themselves to their RO.

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Aqua99

· #3 · Mar 19, 2017

Spectrapure "Economy" RODI 90GPD off amazon. It's cheaper than their website and uses one of the best membranes available. $150

15"x6.5"x16.5" (l x w x h) if you need to fit it somewhere.

I've had several units over the years and this one surpasses them all. If you had to go small you could check out the RO Buddie by Aquatic Life but many people end up fixing leaks and the low output is annoying.

Bump: I use the salty shrimp and it's easy. Mix it to the GH/KH you want then record the TDS. After that I just mix to that same TDS number so I'm not wasting my test fluids.

sfshrimp

Discussion Starter · #4 · Mar 20, 2017

Aqua99 said:
Spectrapure "Economy" RODI 90GPD off amazon. It's cheaper than their website and uses one of the best membranes available. $150

15"x6.5"x16.5" (l x w x h) if you need to fit it somewhere.

I've had several units over the years and this one surpasses them all. If you had to go small you could check out the RO Buddie by Aquatic Life but many people end up fixing leaks and the low output is annoying.

Bump: I use the salty shrimp and it's easy. Mix it to the GH/KH you want then record the TDS. After that I just mix to that same TDS number so I'm not wasting my test fluids.

This looks great. Dumb ? - do you just attach a hose adapter to your sink and run it through the unit into a bucket? Does it take a while or instant? Also - do you need to use seachem prime or conditioners anymore with this? The tap water is good where I live for the fish, but an upgrade might be cool.

zackariah

· #5 · Mar 20, 2017

There are many ways to go about setting up an ro unit. It really depends on how much water you need. You can go with an under sink pressurized tank , or you can get a 55g drum or trash can. Under sink tanks typically are for drinking water. When you look at the gallons per day. That is what the unit can produce in that day. So if your unit produces 90gpd then it will take about 1 hour to get 3.75 gallons. Hence the need for a storage container preferably with an auto top off. The company that I suggested includes the top off with the unit. No seachem prime needed as long as you have a good unit. You would need to remineralize though. That is why I use a 2to1 ratio. 2g of RO to 1g of tap. I used water bottles to figure out what ratio would give me the parameters I'm looking for.

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DaveK

· #6 · Mar 20, 2017

sfshrimp said:
What's the best RO/DI unit to buy for a smallish space under a sink? ...

Also - do you need to add more minerals to RO besides the KH/GH boosters? Would probably use salty shrimp to get a 6gh/3kh if I upgrade to RO.

Almost any RO/DI unit will work just fine. There really isn't that much difference between them. Most of the filters used are interchangeable between vendors.

You don't need to add anything beyond GH and KH but I find it a good time to also add ferts to get the initial levels to where I want them. This is strictly optional.

soc200

· #7 · Mar 20, 2017

I have been using the RO Buddie now for several months and it is working great. It was $60 on amazon shipped. I previously used a much bigger setup from thefilterguyz and it worked great but was MUCH bigger and expensive.

Having used several systems now over many years...I'm not a believer that bigger is better in this situation. My RO buddie brings my tds to 2-4 without the DI (which you can very easily add if you feel compelled.). I've gotten hundreds of gallons out of the RO Buddie and it is still going strong. Replacement cartridges are cheap and easily obtained when needed. Mine is currently installed behind my washer...with a pushfit valve ($4 from home depot) between the supply and the unit to turn my flow on and off. Super simple and absolutely no leaks.

You can also install a float valve into a food safe container (like a big trash can) if you want large supplies of water available at all times. I've done this and it works really well, too. Hope some part of this helps.

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Aqua99

· #8 · Mar 20, 2017 (Edited)

Was thinking more about this and something kept sticking in my mind regarding the ammonia...

I believe it has the ability to pass through the RO membrane much easier than other contaminants (much like CO2 and H2S). Therefore your DI cartridge will pick up most of the work as it follows the membrane in the whole chain of events. Maybe look for one of those systems that runs double DI cartridges, or a color changing DI cartridge and change it well before it completely changes color, or just test your stream once a month to keep track, if it's really a concern. Some companies also market a DI cartridge specifically referencing NH3.

I also remember something about the NH3 often releasing from the DI material when depletion reaches 100% and then showing up in your purified stream (I don't think it was all of the easy to pass through RO membrane contaminants, but specifically the NH3... can't say for certain without looking though).

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soc200

· #9 · Mar 20, 2017

Regarding the ammonia, I would add Seachem Prime (or equivalent) to my water if I was still testing positive for ammonia. Per Seachem, Prime will bind up the ammonia for 24-48 hours, which is more than enough time for the biological filter to nitrify it in a cycled system.

sfshrimp

Discussion Starter · #10 · Mar 21, 2017

What part do I need to connect the sink faucet to the unit? Or is there a way to do it under the sink? I am unexperienced with plubming, but I think I could figure out. I have one of those hose sprayers in the sink and the dishwasher so there is probably some form of connection down there.

Aqua99

· #11 · Mar 21, 2017

The RO unit I bought has a garden hose fitting attached to it. You can get a faucet/garden hose adapter from Home Depot for like $5. All I had to do was unscrew the little aerator thing off the end of my faucet, screw on the adapter, then screw on the supply hose.

If I weren't moving out of this house shortly I'd plumb it in under my sink. For now it's easier to pull it out of my closet, set it on the back of my toilet, hook to the bathroom sink and pump as many gallons as I want into a bucket in my bathtub. No worries if I forget about it this way as it just goes down the drain. Kind of crude... but works easily for me given the situation.

If you look under your sink there's always something you can tap into. Pex plastic is easy to splice a tee into and anything else you can usually just separate a fitting and find/adapt a tee to fit. Hard to tell without knowing what you have under there. The best thing about places like Home Depot is the adapter section.

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soc200

· #12 · Mar 22, 2017

sfshrimp said:
What part do I need to connect the sink faucet to the unit? Or is there a way to do it under the sink? I am unexperienced with plubming, but I think I could figure out. I have one of those hose sprayers in the sink and the dishwasher so there is probably some form of connection down there.

You can certainly connect the filter to the cold water line under the sink and it will work well. If you have a clothes washer, you can also connect it to the water faucet with a Y connector (picture below). If you live in a place where you are always above freezing, you could connect it to any garden faucet. You can even buy quick connectors for standard faucet connections. The options are really endless depending on your needs.

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sfshrimp

Discussion Starter · #13 · Mar 24, 2017

Looking like I'll just roll like this for a while with my pink bucket. I only need 5 gallons at a time so this should work ok.

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soc200

· #14 · Mar 26, 2017

I'm in the same boat. I keep 5 gallons of water ready in a bucket. I marked off each gallon on the side of the bucket with a marker and I set a timer on my phone. By the time I've drank my coffee and engaged in some aquatic therapy (trimming)...my water is ready for next week.

sfshrimp

Discussion Starter · #15 · Mar 29, 2017

soc200 said:
I'm in the same boat. I keep 5 gallons of water ready in a bucket. I marked off each gallon on the side of the bucket with a marker and I set a timer on my phone. By the time I've drank my coffee and engaged in some aquatic therapy (trimming)...my water is ready for next week.

Lol. I didn't realize how much water these units waste. It's kind of a bummer. At my friend's house I want him to chain the water into his bamboo garden from the second floor.

Does anyone know if you need to use prime with RO water? Or is it not needed?

soc200

· #16 · Mar 29, 2017

sfshrimp said:
Lol. I didn't realize how much water these units waste. It's kind of a bummer. At my friend's house I want him to chain the water into his bamboo garden from the second floor.

Does anyone know if you need to use prime with RO water? Or is it not needed?

From the AquaticLife website:

"Designed to provide a reliable source of economical filtered water for aquarium use, all systems use Thin-Film Composite (TFC) Membranes in conjunction with Carbon and Sediment cartridges to effectively and efficiently remove harmful substances such as heavy metal ions, dissolved solids (TDS), Chlorine and particulate matter from municipal tap water."

I don't typically add Prime. You do, of course, need to re-mineralize your RO water to add the necessary minerals back...ie. Seachem Equilibrium or similar product.

sfshrimp

Discussion Starter · #17 · Mar 29, 2017

soc200 said:
From the AquaticLife website:

"Designed to provide a reliable source of economical filtered water for aquarium use, all systems use Thin-Film Composite (TFC) Membranes in conjunction with Carbon and Sediment cartridges to effectively and efficiently remove harmful substances such as heavy metal ions, dissolved solids (TDS), Chlorine and particulate matter from municipal tap water."

I don't typically add Prime. You do, of course, need to re-mineralize your RO water to add the necessary minerals back...ie. Seachem Equilibrium or similar product.

Using salty shrimps GH/KH salt brine. Thanks for the info. Without a chlorine or chloramine test kit at hand, I guess it's just hope that it's removed? Maybe I'll try a glass of RO water when I am at home close to the bathroom for the negative ions.

soc200

· #18 · Mar 29, 2017

sfshrimp said:
Using salty shrimps GH/KH salt brine. Thanks for the info. Without a chlorine or chloramine test kit at hand, I guess it's just hope that it's removed? Maybe I'll try a glass of RO water when I am at home close to the bathroom for the negative ions.

I typically make a new batch of RO water after a water change. Then it sits there until I need it. Chlorine will evaporate from water in 12-24 hours...which is just an added level of protection.

sayn3ver

· #19 · Mar 31, 2017

Ro units typically have prefilters . So normally it's one or two sediment filters and one or two carbon blocks. Typically, if the incoming water is treated with chlorine then the carbon removes that before the membrane.

With chloramine a typical carbon block may not touch it or may only remove some as chloramine is chlorine bound to ammonia and requires a catalyic carbon and longer dwell time.

The simple answer is you shouldn't need prime after a carbon block or an ro filter.

Chlorine and chloramine will shorten the life of the ro membrane from what I've been told.

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