Help with AquaFX RODI Unit

[Jaws]

Hey guys. I found a good deal on a very slightly used AquaFX RODI unit that someone locally is selling. They're advertising that it's 300GPD and based on the pictures it's this unit right here:

http://www.aquariumwaterfilters.com/index.php?page=shop.product_details&flypage=flypage-ask.tpl&product_id=22&category_id=12&vmcchk=1&option=com_virtuemart&Itemid=1

The thing I'm worried about is this unit can also be as low as 50GPD but you can pay extra to make it a 300GPD filter based on that link. The person selling it doesn't know where to look to make sure it's a 300GPD unit and I was hoping someone here might be able to tell me where I can look to confirm it. Thanks in advance :)

[Myka]

The 300 GPD AquaFX will have either TWO 150 GPD RO membranes or THREE 100 GPD RO membranes. If there is only one membrane then it is definitely not 300 GPD. Get the seller to remove the RO membrane(s) and read the side of it which will state the GPD rating. If there are multiple membranes, add the GPD together.

As a side note, not all membranes are made equal. Filmtec is considered industry standard, and is the only brand I buy. Be aware that 100 GPD RO membranes may be as low as 90% rejection (the 75 GPD and 150 GPD memranes are 98%) which means up to 10% of the tap waters' TDS will get through the membrane which means more for the DI resin to take out which means you will go through more DI resin, plus the DI may not be able to remove all the remaining TDS depending what it is that made it through.

[Jaws]

Thank you!

Sent from my Lumia 800 using Board Express

[MMAX]

I have an AquaFX RO/DI 100gpd unit that is a carbon copy of the one pictured. I looked on another site and the 200gpd will have 2 membranes and the 300gpd will have 3.

[Realshow]

I currently have the aqua fx in 150 gpd.
I will not replace the membranes or filters again. I found aqua safe sells their ro/Di units for a more economical price to buy new.
I am going to order the 150 gpd with all new supplies including tds meter,auto shut off etc.6 sets of replacement filters and Di resin refil for $178 + shipping.
I was referred to them through a friend on another forum. there is also a i believe a 15% discount if you use the code " BCAquaria"
Im not trying to change your mind but its worth researching the cost of replacement parts over a whole new unit.

[Borderjumper]

And aqua safe is right here in town! I have an extra pretty much complete system I will sell.. PM if interested.

[Jaws]

I've actually got a 100 GPD Aquasafe RODI right now. I was just thinking a larger ne might be better for a 700G system. What do most people use on a large system like that? I plan on changing 100G's every two weeks.

[Aquattro]

That unit you're looking at isn't 300GPD. And it looks well used, AND the seller probably doesn't know what it is. I notice he's also selling a 175w MH for 100 bucks, also not worth it (I know because I gave it to him for free :))

Joel is selling his 1000GPD unit for 250, might be more what you're looking for.

[BlueTang<3]

This may not help much but my new system is about 550 gallons so far and have 2 90 gallon poly tubs that I run with float valves. I have always used the vertex 100 gpd rodi units it allows me to turn it on and once its full the vertex has pressure sensors that turn off the unit. I also run water on the floor sensors as a backup if it failed but havnt had an issue yet been doing it like that for 3 years with my old system. But I also plan kn changing 90 gallons bi weekly, nothing worse than waiting for water or in emergency so that's why I have 2 tubs but they are cumbersome and take up a lot of space.

[Myka]

www.bulkreefsupply.com (http://www.bulkreefsupply.com) has 300 GPD Spartan RO/DI systems for $420. Pretty good price imo. I'm waiting to hear back availability from my LFS since I prefer to buy locally, but if all else fails I will buy the Spartan.

One thing to keep in mind is that it is much better for your filters (particularly the RO and the DI) if you use the system less often for a longer period of time. I have two 65-gallon drums. When one is empty I start using the second one, and refill the first one. There is a float valve to turn it off when it fills up (although usually I am watching and will turn it off before it hits the float valve, but I will not have the system turn itself on...that is recipe for disaster that I've seen too many people go through. In this way, I never make less than about 60 gallons at a time. I use about 80 gallons per week though, and my patience wears thin so I'm looking at upgrading from my current 150 GPD system to 300 GPD so I can fill my new 100-gallon containers faster.

My current system is an AquaFX Barracuda that I replaced the RO with a Filmtec 150 GPD membrane and am using a 75 GPD flow restrictor so I am getting about 1:1.5 good:waste. My RO membrane is about 2.5 years old now and is starting to clog up from not having the recommended amount of waste water flowing over it. It is still only putting out 8 ppm (tap water is 240-300 ppm), but is only running about 120 GPD at 75F and 62 psi. I'm going to try cleaning it with citric acid. That's what I chose to do though since I hate wasting so much water. BRS only charges $65 for the 150 GPD Filmtec membranes so I don't mind replacing it every 2-3 years. I think all the Filmtec membranes suggest 1:4 good:waste which is what you will get if you match the flow restrictor to the membrane GPD.