Skimmer or RO/DI Unit

[chwcdw]

If you need both but could only get one to start, which is more important?

[Southern Boy]

I would say the RODI unit to insure you were putting quality water in to start with to stop alot of problems befor they start.I ran my 180 for 6 months with no skimmer and was happy with the quality and have seen some beutiful tanks that run skimmerless.But I also think that a protien skimmer should be standard equipment because it does make a difference and helps decrease water changes and keeps the water a lot clearer.Also you can get rodi water at a LFS wher you can't get a skimmer 50 cent at a time.Whats the tds in the water where you are at?My folks just got a place in Sunbright that I hope to be stayin at soon and the water straight out the well only had a TDS reading of 125.Don't get me wrong, it's not perfect but it's alot better than my city here at like 650!

[poppin_fresh]

No question... RO!

Pure water is a must for a healthy aquarium. A skimmer is a great investment, but not absolutely necessary. You can make up for not having a skimmer with more frequent water changes....with your now pure water.

[Tracy R.]

Get the skimmer. You can always go to your LFS to purchase your water but the skimmer needs to be doing it's job 24-7.

[demonsp]

If you dont have a source like wall mart or i use watermill.Then ro unit. But if you see the gross , stinky , disgusting , ect.. stuff a skimmer removes then that would be a tougher question. Go ro then do weekly changes and get that skimmer asap. Of course the amount of stock you have is a major factor. GL

[funman1]

I have seen tanks with out skimmers that look awesome, and I have seen tanks without RO after 6-8 months, GO WITH THE RO

[demonsp]

IMO a good skimmer will let you max your stock out. I would never have a fully stocked tank without a skimmer. But i do hear of people not useing them. I wouldnt. GL

[clarkiis]

I think I would choose skimmer....

but thats with me using natural seawater for water changes(atleast 10gal a week) and RO water for top off for a 90gal 120gal total water. Only go through 5 maybe 7 gallons of RO a week.

If I were mixing my own salt the size of the tank would be the only deciding factor for me. If it were a very large tank I would go RO first skimmer second. If it were 100gal, maybe 75gal, or less skimmer first RO unit 2nd.

[AZDesertRat]

RO/DI easily. Water is the single largest ingredient in you system and everything in the tank depends on it. Buying water can be risky as most LFS or Water stores don't pay as much attenetion to quality as they do quantity. Having your own RO/DI you are in control of the maintanance and quality.

[mr_o98]

RO/DI

[chwcdw]

Thanks for confirming my thoughts!

The RO unit has been ordered, but the skimmer wont be far behind. I'm still researching which skimmer I want anyway. Too many choices out there!

[poppin_fresh]

You should look for a good deal on a used skimmer if you can.

I bought a used H & S A150 for $200. Not too bad considering its a $600 skimmer. You really do get what you pay for in a skimmer too. The H & S is a performance monster.

[AZDesertRat]

Hope you did your homework and bought a good one and not an e-bay special. There is a big difference in quality.

[moze229]

Hey AZDesertRat,

Not to steal a thread, but you've helped me before and I value your opinion. Since you brought up quality RO units - isn't the media used the most important part of the 'quality' in an RO unit? Of course, that would be leaving out the endless variables that make up the add-ons such as pressure gauges, top-off add-ons, inline TDS, etc. I'm sure there are some doosies out there, but for the most part all of the units are put together with the same pretty much the same stuff? From what I understand, as long as you have sediment removal, chlorine/chloramine removal and DI, you're good as long as you use quality media.

Matt

[chwcdw]

100gpd Typhoon III. I did however, look at several on ebay, and not all look bad.

I was under the same impression as moze229 with the quality of the media being the most important aspect of an RODI unit, but not being one to buy the cheapest of anything, I went a head with the Typhoon because of the good comments made in the various threads here.

I would be interested to hear your thoughts AZDesertRat, as it looks like you do a little work with water.

[AZDesertRat]

The quality of the filters is most important, but there is also a difference in the quality of the housings and fittings too. Good RO/DI units are noticably heavier due to the better construction of the housings, the plastic is better and thicker. We are hearing about the lack of quality in Chinese imports every day now, the same goes for RO units, most of the e-bay quality units are coming from there. The quality of the components can vary greatly as there is little or no quality control. Some include membranes which are not even ANSI/NSF approved for sale in the US. Some even falsely advertise being made in the US. Don't believe it for a minute. You cannot build a good RO/DI using high quality components in the US and sell it for $60, it just doesn't work that way.

The difference is obvious when you start to look closely at the various units for sale. First look at the micron ratings for all the filters, some don't even tell you what they are, others use large micron ratings, BIG RED FLAG!
Next look at the membrane; Some use a 100 GPD Nanofilter not even and RO membrane at all (Sorry chwcdw, this includes you) that is only 90% efficient instead of a Dow Filmtec trur RO membrane that is 98% efficient. The difference is most apparent when you consider that for every 2% you increase the RO efficiency you DOUBLE the life of the DI resin.
Some don't tell you who makes the membrane, others say "USA". Yet others claim 110 or 125 GPD, but if you do some research you will find not one single US manufacturer winds a 110 or 125 GPD RO membrane. Another RED FLAG

Some include a little horizontal clear tube with 6 oz or so of who knows what resin bobbing around inside it. This is not a DI filter in any way shape or form. A DI filter is a standard 10" canister containing a cartridge that is in most cases refillable and holds 20 oz of nuclear or semiconductor grade DI resin that is packed tightly and flows from the bottom up. Loose resin floating around leads to short circuiting and poor treatment since not all water comes into contact with the resin. In some cases you will never ever see a 0 TDS reading no matter how good your water is to begin with. Yet another RED FLAG

Look at the prefilter. Is it a 1.0 or 0.5 micron filter? Beter yet it could be a 0.2 micron prefilter which has 10x thesurface area of a normal filter and is actually small enough to filter out some viruses and bacteria unlike any other filter on the market. You will probably find a 10 micron filter or again it may not even tell you what it is. RED FLAG

Carbon blocks vary greatly. You want a 0.5 micron Chlorine Guzzler or Matrix type carbon block. They are rated for up to 20,000 gallons of normally chlorinated water. GAC cartridges are exhausted in as little as 300 gallons! Thats 30 gallons total through the unit including the 4:1 waste. That means after 60 gallons of RO/DI its shot, kaput, worn out. 240 waste and 60 good is 300 gallons! 10 micron blocks may do 1000 gallons if you are lucky and a 5 micron carbon might do 2,000 gallons. Again thats total water through your unit including waste and product or good water. Even bigger RED FLAG!

I won't even go into housings, John Guest fittings, pressure gauges, flow restrictors, autoshutoff valves etc.

I hope this opens your eyes and helps you to evaluate the different units available. Again "THERE IS A DIFFERENCE IN RO/DI UNITS, AND YOU GET WHAT YOU PAY FOR".

[AZDesertRat]

Now reasons why you want good filters.
The prefilter and carbon block are there to protect the RO membrane and allow it to do its job effectively. The prefilter traps sediment and solids so they don't get to and damage the membrane. The smaller the micron rating the better for a couple of reasons. One is whatever passes through the prefilter gets trapped by the carbon block if it is sized properly but it also shortens the life of the carbon block as it is now pulling double duty. It was not designed to be a sediment filter.
Large micron ratings do a poor job of trapping solids so they pass to the carbon as mentioned and some then get passed to the membrane fouling its surface.
Carbon blocks as mentioned previously are there to remove chlorine but also to remove organic chemicals too. The better the filter the better job they do. A 0.5 micron block has massive amounts of surface area in its micro pores. If properly protected by a high quality prefilter they can go the full 20,000 gallons they are rated at with ease. Even if you change them every 6 months as recommended you still get much better filtration than with GAC or a cheap block.

As mentioned before some membranes are not even really Reverse Osmosis filters at all, they are micro or nano filters which are not nearly as effective. Thye are also not approved for use in drinking water systems in the US according to the National Sanitation Foundation (NSF) which certifies anything that comes into contact with water. Be very careful when evaluating filters and membranes, there are several different ANSI/NSF certifications and even though it may say NSF on th label look closely ate the number next to it. Case in point is the Dow Filmtec 100 GPD membrane, it is NSF certified for "POOL AND SPA USE ONLY" according to the NSF. That means it is less efficient than a RO membrane or 90% instead of 98% rejection. 90% rejection is a much larger micron size and cannot guarantee virus and bacteria removal like RO can. Not to metion like I said before "For every 2% you increase the RO efficiency you double the life of the DI resin."

A more efficient membrane makes DI resin last longer and work better. RO by itself is not real efficient at phosphates, silicates and nitrates, they are some of the things that are tougher for it to remove. The combination of RO and a good efficient DI cartridge can tackle things like this though if they are properly designed and maintained. Never ever rely on color changing DI resin. Its a poor indicator at best. Chances are by the time it turns colors its too late and you are passing phosphates and may not know it.

A good tool to tell you the condition of your equipment is a handheld TDS meter. Inline meters are the craze right now but they will never stand up to a good handheld. First off they are not temperature compensated and if you water and air temperature are not EXACTLY the same you will be off, sometimes significantly. Inlines are measuring air temperature not water temperature. They also are not portable and cannot bne used as such, they require flow past the probe to register and cannot just be immersed in a glass of water.

Another good tool is the pressure gauge. Pressure drop makes a huge difference in RO production and quality. Install at least one gauge aftre the carbon block and before the membrane and watch the readings often. I prefer two gauges myself, I also have one on the incoming tap water line so I can see the difference between the two at a glance.

[moze229]

Wow - thanks for the detailed info! I'm running 1 micron sediment, and two Matrix type NSF rated carbon blocks. When I started again last year, I also added the standard 10" DI canister. The membrane is a Filmtec 50 or 75 GPD, I don't remember. I've got the pressure gauge just before the RO. My hand held TDS has read 0 from the beginning - (about 7 months ago). Sounds like I'm doing OK.

I'll let chwcdw get back to his thread now

Matt

[chwcdw]

Wow, thats a lot to take in. I really appreciate the input. I did find in my search that it is very difficult to find any information that makes sence to the average person. You have opened my eyes big time!

Is there a unit or units that you would recommend that I look at? Unfortuately, my budget is not as large as some guys around here, but I certainly don't mind spending a little more to buy a quality product that will last. It's not too late to cancel my order.

[AZDesertRat]

The very best unit on the market today is the Spectrapure MaxCap RO/DI system. It may cost more initially but it will give you greatly extended DI life, guaranteed 98+% rejection rate RO water (mine is currently at 99.33% rejection after 13 months of heavy use), and greatly extended RO membrane life due to the premium quality prefilters and carbons they use. I tested one for them 18 months ago then bought my own based on the test results. Nothing available today even comes close in quality or performance.
If the MaxCap is out of your budget then look at:
www.buckeyefieldsupply.com - 75 GPD Premium series
www.thefilterguys.biz - 75 GPD Ocean Reef +1
www.melevsreef.com - Reefkeeper
www.purelyh2o.com - 75 GPD Optima Professional or Optima Vision

All are very good units. Some include things like pressure gauges, either handheld or inline TDS meters, autoshutoff valves sometimes with a float valve, RO bypass valves, flush valves and even adjustable flow restrictors. Look at each closely and see which ones have the features you are looking for then contact the vendors and ask questions. They will all be happy to talk with you without any pressure.

[chwcdw]

Wow, thats a lot to take in. I really appreciate the input. I did find in my search that it is very difficult to find any information that makes sence to the average person. You have opened my eyes big time!

Is there a unit or units that you would recommend that I look at? Unfortuately, my budget is not as large as some guys around here, but I certainly don't mind spending a little more to buy a quality product that will last. It's not too late to cancel my order.

[chwcdw]

Don't know how I did it but I double posted that last message.

Oops.

Thanks again, I will definately check those out!

[loosecannon]

Skimmer.

[RickySan]

i would get a skimmer and buy the ro/di water from the LFS...im sure as said above

[AZDesertRat]

Do you know the quality of the water at your LFS? Will they test it for you upon request?
Don't chance it.