Auto Top off and RO/DI Units

[FAMLYREEF]

Hey All,

I'm sure this is a redundant topic in the aquatic world.

What would you say are the top 3 brands and or "systems" when it comes to RO/DI units and Auto Top-Offs?

There is a member on here with this post (https://www.reef2reef.com/forums/se...f-reverse-osmosis.html?highlight=auto+top+off) and it looks like a great products, but I wouldn't know any difference.

Please fill me in with what you have experienced!

 

[AZDesertRat]

Top 3 reef quality RO/DI is easily www.spectrapure.com , www.buckeyefieldsupply.com and www.purelyh2o.com . Top 3 ATO systems are www.spectrapure.com, www.tunze.com and www.elos.com . All have a lengthy history in the reef and aquatics industry.

 

[Tek]

For RO/DI it depends on how many stages it comes with and the GPD flow rate. I personally like something at 125GPD+ since I hate waiting forever to filter water.
My RO/DI unit also has 2 DI filters instead of one just for extra assurance. I have never really centered on a brand and pick via features.

For auto top offs I select it for ease of use and mounting. I have used a 5.00 switch which works as well as a 60.00 branded system.

 

[SloppyJ]

I just put a tunze ATO on my tank this morning. I was highly impressed with it.

 

[AZDesertRat]

No vendor makes a 125 GPD RO membrane.
You get them in 25, 50 and 75 GPD versions from Dow Filmtec and 60 , 75 and 100 GPD versions from GE Osmotics. Thats really misleading though as they are bsaically the same thing in reality since GE says 100 GPD at 65 psi and 77 degrees F while Dow says 75 GPD at 50 psi and 77 degrees. When you lay the graphs over each other you see they both make 75 GPD at 50 psi, 90 GPD at 60 psi and 100 GPD at 65 psi, its the delivery pressure that mostly dictates the flow in GPD.

Stages is a word dreamed up by the ebay vendors who are selling low end drinking water systems with granular activated carbon rather than solid extruded carbon blocks and a couple little horizontal tubes with some DI resin bobbing around in them and calling them 5, 6 or 7 stage reef systems. Thats BS. You need 4 stages for a reef quality RO/DI, a low micron sediment filter to protect the single low micron carbon block which protects the RO membrane which in turn acts as pretreatment for the single 20 oz vertical refillable DI filter. Thats it 4 stages. If you want more bang for your buck adding an additional DI stage is a good investment but additional horizontal stuff or sediment or carbons are a waste of money and actually can hurt not help.

 

[Tek]

Mine was sold as a 125GPD on Ebay. I just did the math and it produces 80-90GPD at around 37 psi.

 

[Downbeach]

Mine was sold as a 125GPD on Ebay. I just did the math and it produces 80-90GPD at around 37 psi.

What are you measuring your pressure with? It's suggested that you have a minimum of 50 psi, without having issues with performance and efficiency. A booster pump will help.

 

[dwilliams87]

No vendor makes a 125 GPD RO membrane.
You get them in 25, 50 and 75 GPD versions from Dow Filmtec and 60 , 75 and 100 GPD versions from GE Osmotics. Thats really misleading though as they are bsaically the same thing in reality since GE says 100 GPD at 65 psi and 77 degrees F while Dow says 75 GPD at 50 psi and 77 degrees. When you lay the graphs over each other you see they both make 75 GPD at 50 psi, 90 GPD at 60 psi and 100 GPD at 65 psi, its the delivery pressure that mostly dictates the flow in GPD.

Stages is a word dreamed up by the ebay vendors who are selling low end drinking water systems with granular activated carbon rather than solid extruded carbon blocks and a couple little horizontal tubes with some DI resin bobbing around in them and calling them 5, 6 or 7 stage reef systems. Thats BS. You need 4 stages for a reef quality RO/DI, a low micron sediment filter to protect the single low micron carbon block which protects the RO membrane which in turn acts as pretreatment for the single 20 oz vertical refillable DI filter. Thats it 4 stages. If you want more bang for your buck adding an additional DI stage is a good investment but additional horizontal stuff or sediment or carbons are a waste of money and actually can hurt not help.

I agree completely, the only thing I have to disagree with is the extra carbons. Unless you are checking for chlorine/chloramines, you don't know for sure that your carbon filter is doing it's real job, removing chlorine. I work in Dialysis as a Biomed and the most important thing when it comes to water treatment is chlorine removal. In my line of work, we have large carbon tanks that are backwashed everynight, but occasionaly we will have what we call chlorine breakthrough which is where chlorine gets by our first tank, the worker tank, and is found at our 2nd tank, or backup/polisher tank. Unless you are extremely diligent and check your chlorine level, how do you know its not there? This is the reason I use a secong carbon filter, for that warm and fuzzy feeling. I'm not sure exactly what happens to fish internally when exposed to chlorine, but I know as humas, if we have chlorine put into our blood stream, we undergo hemolysis which is where your blood cells start bursting, it doesn't take long until death. Now, I know we arent injecting chlorine into their bloodstream but I don't know how it affects them, so rather than checking for chlorine which alows for human error I use my warm and fuzzy second carbon filter. How do you mean they can hurt not help? Are you saying that the extra buildup can cause problems? If this is the case, then I agree, but thats' where diligent filter changes comes in. Water is the most important even fundamental compound in this world as it is what the earth is mostly made of. I choose to not skimp when it comes to the quality of the water that I am exposing my reef to.

 

[Tek]

What are you measuring your pressure with? It's suggested that you have a minimum of 50 psi, without having issues with performance and efficiency. A booster pump will help.

I have an inline pressure guage on my unit. It filters the amount I need and none of my tanks are very large. TDS is at 0 and my tanks have not had any high PO4 or algae issues.

 

[AZDesertRat]

In the reef hobby we use solid extruded carbon blocks in the 1 micron or less range which is much much more efficient than granular activated carbon. One good Matrikx +1 0.5 or 0.6 micron carbon block in the 10" length is easily good for up to 20,000 gallons of normally chlorinated OR chloraminated water as long as it is well protected. Dual carbons are a waste of money AS LONG AS you use a good quality sediment filter of the same or lower micron rating as the carbon and an absolute rated sediment filter is far better than a nominal rated sediment filter. If you use a 5 or 10 micron sediment filter then all bets are off since silt and colloidal materials can pass right through fouling or plugging the carbons billions of tiny pores where the chlorine (NOT chloramines) is adsorbed. Carbon does not remove chloramines, only chlorine and VOCs. DI resin takes care of the ammonia portion of chloramines NOT carbon. This is very misunderstood and often misrepresented and confusing.

Tek, you probably have a Dow Filmtec 100 GPD Nano Filter or NF rated at only 90% rejection rate or removal efficiency, not to be confused with a 75 GPD Reverse Osmosis or RO membrane rated at 96-98% sustained rejection rate or removal efficiency. The 100 is labelled by the ANSI/NSF as "Pool and Spa Use" and not approved for drinking water in the USA while the 75 GPD RO membrane is for drinking water use as is the GE Osmotics 100 GPD RO membrane. Huge difference when it comes to TDS and the life of your DI resin. A vendor who represents the Dow 100 as reef quality gives the industry a black eye and needs to be run off, ask any legitimate RO vendor and they will do everything they can to talk you out of the Dow 100 as it is not as good a membrane and designed for a different purpose.


With RO/DI you really do get what you pay for and ebay is not usually where you want to look. A bit of research turns up a lot of information.

 

[dankreef]

I just put a tunze ATO on my tank this morning. I was highly impressed with it.

This. Only one to buy. Complete setup $200 super ez install w magnets ect.

Brs 5stage for ro/di you wont be disappointed with these two. Clear canisters you can see filters ezmode install.

 

[Zack]

This. Only one to buy. Complete setup $200 super ez install w magnets ect.

Brs 5stage for ro/di you wont be disappointed with these two. Clear canisters you can see filters ezmode install.

Plus 1! I have these two items as well. Just can't beat it!

 

[spscrazy]

I am looking to get a new ro/di filter was wondering how important or not is the ro membrane flushing kit?

 

[AZDesertRat]

The flush kits that bypass the flow restrictor are a waste of money. Adding a DI bypass valve to flush TDS creep from the treated side of the RO membrane is a good $10-$15 investment though.

 

[FAMLYREEF]

Who makes BRS RODI or branded products in general for them? Or do they manufacture their own brand?

You guys have given me much to think about.

 

[AZDesertRat]

The RO vendors all buy their components from places like Dow Filmtec, GE Osmotics, Puratek, KX Carbon, John Guest etc.
They only assemble the components. The better ones such as we see mentioned often on these forums assemble them themselves here in the states, most ebay vendors import them by the shipload from China and Taiwan so you have no idea the quality or age of what you are getting so its best to stay away from them in general.
Some vendors go a step or two further and have research and development and test facilities where they can actually put systems through their paces stressing the components and filters to ensure you get only the best, Spectrapure is the main example here. Spectrapure also treats all their RO membrane with a proprietary process which is documented to improve both the rejection rate and the GPD over normal membranes from the same manufacturer and have been doing so for decades. They also research and blend their own reef specific DI resins which last up to 3-5zx longer than comparable resins. This is very unique and well worth any extra it may cost which at this time with units on sale they are actually less expensive than others even though they excel.

In general you cannot go wrong with pretty much any vendor mentioned here such as Spectrapure, Buckeye Field Supply, who also offers tested RO membranes now, PurelyH2o, Melevs Reef, BRS, AWI and a few others I forget. Look for things that matter like Dow Filmtec or GE RO membranes, llow micron and preferrably absolute rated sediment filters, 0.5, 0.6 or 1.0 micron extruded carbon blocks, inline pressure gauges, handheld TDS meters over inlines, capillary tube flow restrictors and most of all full size 20 oz vertical refillable DI filters with no less than nuclear or semiconductor grade DI resins. Things like two carbons, small hroizontal DI filters, flush kits and such really have no value.

 

[SloppyJ]

Filterguys really impressed me. Call them up when you order and talk to them. Super informative group of guys.

 

[AlexAquaFX]

In the reef hobby we use solid extruded carbon blocks in the 1 micron or less range which is much much more efficient than granular activated carbon. One good Matrikx +1 0.5 or 0.6 micron carbon block in the 10" length is easily good for up to 20,000 gallons of normally chlorinated OR chloraminated water as long as it is well protected. Dual carbons are a waste of money AS LONG AS you use a good quality sediment filter of the same or lower micron rating as the carbon and an absolute rated sediment filter is far better than a nominal rated sediment filter. If you use a 5 or 10 micron sediment filter then all bets are off since silt and colloidal materials can pass right through fouling or plugging the carbons billions of tiny pores where the chlorine (NOT chloramines) is adsorbed. Carbon does not remove chloramines, only chlorine and VOCs. DI resin takes care of the ammonia portion of chloramines NOT carbon. This is very misunderstood and often misrepresented and confusing.

Tek, you probably have a Dow Filmtec 100 GPD Nano Filter or NF rated at only 90% rejection rate or removal efficiency, not to be confused with a 75 GPD Reverse Osmosis or RO membrane rated at 96-98% sustained rejection rate or removal efficiency. The 100 is labelled by the ANSI/NSF as "Pool and Spa Use" and not approved for drinking water in the USA while the 75 GPD RO membrane is for drinking water use as is the GE Osmotics 100 GPD RO membrane. Huge difference when it comes to TDS and the life of your DI resin. A vendor who represents the Dow 100 as reef quality gives the industry a black eye and needs to be run off, ask any legitimate RO vendor and they will do everything they can to talk you out of the Dow 100 as it is not as good a membrane and designed for a different purpose.


With RO/DI you really do get what you pay for and ebay is not usually where you want to look. A bit of research turns up a lot of information.

Some great information here, AZ! The more we can educate, the more headaches we can help people avoid, right!

There is a few things I disagree with though.

In the reef hobby we use solid extruded carbon blocks in the 1 micron or less range which is much much more efficient than granular activated carbon.

This statement is actually backwards. As you mentioned later in your post, Carbon works through surface area pore "Adsorption". When carbon blocks are glued, we lose 30% or more of the surface area reducing our efficiency.
Also, rating carbon filters on micron (Pore Size) is not very important, but your sediment is. For example, if you have a .05 micron sediment, there is no necessity for a .06 carbon. Anything that small will have been taken care of by the sediment filter. So if you're at your LFS and they only have 1 micron carbon but your sediment is rated smaller then that, I wouldn't sweat it!

Dual carbons are a waste of money AS LONG AS you use a good quality sediment filter of the same or lower micron rating as the carbon and an absolute rated sediment filter is far better than a nominal rated sediment filter.

Dual Carbon, in my opinion, is not a waste of money and sometimes even a necessity. Carbon filters, as AZ mentioned, remove chlorine and what makes this important is chlorine destroys RO membranes - the most expensive filter on your unit. With dual carbon you have a safety net. Life gets busy sometimes and you don't change those filters on time. With a single carbon, that chlorine gets through and costs you big - where a second carbon would have saved you!

Now let's gets to chlroamines! Which are gaining massive popularity amongst city treatment, ending up in your tap water. A standard carbon does not remove chlromines, as AZ said. The BEST result that we could expect is to remove the Chloride ion from the compound and be left with free Ammonia, which is why some aquarists will test for ammonia in their RO water but not their tap water. Yes, DI resin can be used to remove that free Ammonia. Infact, you could run tap water through DI only and get 0PPM but it would exhaust VERY quickly. The reason we don't do this is because it's not cost friendly. It's cheaper to use a granular activated carbon (GAC) to deal with that free ammonia then to leave it for the DI Resin. DI resin is one of the most expensive filters on a RO/DI unit, so we want to give it the least amount of work as possible! This brings me to an example where dual carbon is needed, in our AquaFX NH2Cl blaster a dual pass over GAC is imperative, as the amount of chloramines that are reacted out is directly related to contact time.

A vendor who represents the Dow 100 as reef quality gives the industry a black eye and needs to be run off, ask any legitimate RO vendor and they will do everything they can to talk you out of the Dow 100 as it is not as good a membrane and designed for a different purpose.

Now AZ, I love you my fellow water nerd, but I have to defend 100GPD membranes (at least ours!). Our 100GPD membranes are NOT considered Nano Filter - we use DOW flat sheets to make up our TFC RO membranes the difference is significant when comparing nano to TFC!

We carry a 98% stabilized salt rejection on our 100GPD membrane - not a 90%! Not all 100GPD membranes are evil, lol!

 

[AZDesertRat]

Rating carbon blocks by pore or micron size is very important. Take a box full of marbles anda box full of BB's, which has more surface area and will filter better? The BB's of course. When they steam extrude carbon blocks the smaller micron sizes have much more surface area, pockets or pores to adsorb the chlorine, thus the 20,000 gallon rating versus the 6,000 or 9,000 gallon rating until exhaustion. yes we do lose some efficiency but it is more than made up with better quality carbon versus even just a few years ago.

For dual carbons I stick with the above, better carbons do a better job and research shoes two are not better in this case. If you do decide to use a GAC carbon, ALWAYS put a low micron sediment filter after it to trap the fines that are produced as the carbon erodes or degrades. My philosphy is everythinmg you add, dual carbons, an additional sediment filter etc, has an associated headloss andan additional unnecessary cost so fewer, BETTER filters are much better than a bunch of less efficient filters and the membrane will perform better as the headloss is lower. Besides the fact your wallet will be happier. Chloramines are not the enemy people mistakenly make them out to be:
Chloramine and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
GENERAL INFO ON REVERSE OSMOSIS
More detailed explanation on Chloramines, RO membranes and Carbon Filters... - Reef Central Online Community
Chloramines - Reef Central Online Community
Only about 30% of the water utilities in the US use chloramines and the residuals or concentrations are in the 0.5 to a maximum of 4.0 mg/L range so nothing high is encountered and no problem for a good single carbon block and more importantly good DI resin with good contact time. Keep in mind, most granular carbons have a useful life as little as 300 to 600 TOTAL gallons per cartridge, thats 60 to 120 treated gallons at the normal 4:1 waste ratio. GAC is not the answer. Catalytic carbon is a little better but still has a short uesful life compared to a 0.5 or 0.6 micron carbon block at 20,000 gallons, let the end user be the judge.

Are you telling me you wind your own membranes in house? If so I would like to see you test data. In over 30 years in the water industry I have yet to see a winder produce a membrane as good as Dow Filmtecs even when using their materials. What ANSI/NSF rating do your membranes carry? What numbers do you use for your 100 GPD rating, 50 psi and 77 degrees like Dow or 60-65 psi like some other vendors who are really selling a 75 GPD membrane at 50 psi which is more the normal pressure found in most homes.

You are right not all 100 GPD membranes are evil but the only two I have seen worth their weight is the true Dow Filmtec and the GE.

 

[AlexAquaFX]

It's cheaper to use a granular activated carbon (GAC) to deal with that free ammonia then to leave it for the DI Resin. DI resin is one of the most expensive filters on a RO/DI unit, so we want to give it the least amount of work as possible! This brings me to an example where dual carbon is needed, in our AquaFX NH2Cl blaster a dual pass over GAC is imperative, as the amount of chloramines that are reacted out is directly related to contact time.

Sorry about that, this is supposed to say Catalytic both times. I was referring to using Catalytic carbon to react out Chloramines, rather than using your DI resin to deal with the free ammonia left behind by a standard carbon.
What are your feelings on that? Why is it more cost effective to use DI resin opposed to Catalytic Carbon in the case of Chloramines.

We do not roll our membranes in house, but they are manufactured here in the US.
When it comes to our membranes our test conditions are only 50PSI at 77° with a maximum 98% stabilized rejection, which we feel is great pre-treatment for our DI resin.
Also our ANSI/NSF certification is in progress and should be complete in the near future!