Best setup for 700+ TDS?

[adrianr514]

Hello @buckeyehydro I currently am running an 8 stage RO/DI system that I have maxed out with goodies. The problem is my tap rings in at an average of 740 and post RO around 60. As you can imagine this eats up my DI rather quickly.

My system is as follows aquatec 8800 booster pump set to 80psi (pressure reading prior to RO membrane) -> HM Flow Monitor -> Aquaboon 1micron Sediment Filter -> UDF activated Carbon (brand unknown) -> coconut carbon (brand unknown) -> dual Dow Filmtec 75 gpd RO membranes -> DI bypass -> Cation DI -> Anion DI -> Mixed bed DI.

So now questions are as follows, is the pressure pump in the right area before any of the pre-filters or should it be post pre-filters prior to RO membrane?

My city treats with chlorine rather than chloramines. Which carbon blocks are best for chlorine?

Are there better membranes rated for such high TDS that I would be better off with?

The following pictures are tap water reading and post RO Reading. Calibrated with 342ppm solution at 77f.

 

[Ron Reefman]

Use the 2 word version and you may have better luck getting their attention. You can tell you got it right if it turns blue when you post it. BTW, I have a very uncommon RO/DI system and Buckeye was super helpful. They even got me a manual and schematic so I could figure out how to plumb my system.
@Buckeye Hydro

Question for you. Are you running the 2 membranes in parallel or in series?

 

[adrianr514]

Use the 2 word version and you may have better luck getting their attention. You can tell you got it right if it turns blue when you post it. BTW, I have a very uncommon RO/DI system and Buckeye was super helpful. They even got me a manual and schematic so I could figure out how to plumb my system.
@Buckeye Hydro

Question for you. Are you running the 2 membranes in parallel or in series?

The waste of the first membrane feeds the second membrane. Raising production and lowering waste.

 

[TheHarold]

The waste of the first membrane feeds the second membrane. Raising production and lowering waste.

You would have more efficiency and production if you just supplied each membrane with the input water.

I upgraded to Spectrapure 99% rejection membranes, which takes my 440 TDS to around 5.

 

[adrianr514]

You would have more efficiency and production if you just supplied each membrane with the input water.

I upgraded to Spectrapure 99% rejection membranes, which takes my 440 TDS to around 5.

Doing so would increase waste water production though and I'm trying not to waste much as I go through about 50 gallons a week between all my aquariums.

 

[Opus]

Doing so would increase waste water production though and I'm trying not to waste much as I go through about 50 gallons a week between all my aquariums.

Is your water expensive? Is it cheaper to waste the water or pay for DI? I use a spectrapure 99% rejection membrane on my 450tds water and my post membrane water is 4. I know you have the 3 di setup so this really doesn't work out number wise for you, but lets pretend you were using a 1 di setup. Your current 60 tds will get around 75 gallons of 0 tds water from a di cartridge. Get that down to 7 tds and you are looking at around 625 gallons from a single di cartridge.

I haven't looked, but Buckeye may have a 99% rejection membrane.

Booster should be hooked up between pre-filters and the RO membrane.

 

[adrianr514]

Is your water expensive? Is it cheaper to waste the water or pay for DI? I use a spectrapure 99% rejection membrane on my 450tds water and my post membrane water is 4. I know you have the 3 di setup so this really doesn't work out number wise for you, but lets pretend you were using a 1 di setup. Your current 60 tds will get around 75 gallons of 0 tds water from a di cartridge. Get that down to 7 tds and you are looking at around 625 gallons from a single di cartridge.

I haven't looked, but Buckeye may have a 99% rejection membrane.

Booster should be hooked up between pre-filters and the RO membrane.

Water isn't expensive however I'd rather pay for DI refills than waste "good" water especially out here in the desert. +

My current Membrane is rated up to 99% but with some tweaking to the Booster pump pressure I got the TDS down to 36 which is a 96% rejection rate. Not back but want more.

I was hoping @Buckeye Hydro could chime in on membranes they have and recommend but they don't seem to frequent the forums. I'll probably shoot them an email.

 

[Buckeye Hydro]

Sorry... for some reason we are not getting notified of posts in this forum. Still need help?

 

[Buckeye Hydro]

Realize the ALL Filmtec 75's have been rated at 99% for years.

 

[Admann]

Your boost pump suction should be after pre-filters and discharge directly to your RO membranes. If I know what I think I do the membranes should be plumbed in series not parallel flow paths.

 

[Buckeye Hydro]

Plumbing membranes in series, with unknown feedwater quality, at marginal pressures... is not an approach we suggest. I understand there is a vendor of aquarium supplies that does.

 

[Bruno_Soares]

Sorry but I couldn´t understand... tap water is 750ppm???

 

[Buckeye Hydro]

With that feedwater, NO WAY IN THE WORLD would I suggest running membranes in your system in series.

 

[Admann]

Why wouldn't you run ROs in series if you are running through sediment and carbon first?

 

[Buckeye Hydro]

Remember that sediment filters and carbon filters have next to no effect on DISSOLVED solids. That's the "D" in TDS. With TDS over 700, no doubt the total hardness is through the roof. The membranes will scale.

 

[Admann]

Remember that sediment filters and carbon filters have next to no effect on DISSOLVED solids. That's the "D" in TDS. With TDS over 700, no doubt the total hardness is through the roof. The membranes will scale.

Yeah, I confused the two. I hope it isn't barium scale.

 

[Buckeye Hydro]

Typically hardness scale is composed largely of Ca and Mg.

 

[Admann]

Typically hardness scale is composed largely of Ca and Mg.

I was just kidding barium sulfate is radioactive, comes from oil wells.

 

[Buckeye Hydro]

Niiiice. Maybe that's why I've never heard of it!

 

[Admann]

Niiiice. Maybe that's why I've never heard of it!

Actually is in the water that comes with the oil and gas. Ingestion of the dust if you allow it to dry, through breathing, cuts or oral ingestion is extremely bad for your longevity.