TDS question

[hazeen]

hi all

Yesterday the RO system installed in my house, I checked the tap water TDS before and after, found the following result

Before : 450ppm
After : 150ppm

Is this IDEL to run the aquarium system ? if not , what can I do more to get less than 150ppm? and what is the TDS range should be?

I called the supplier who advised the output water TDS depends on the input water, therefore we cannot control the TDS in stander, plus the ministry of health will not accept very low TDS as agreed!

Thanks for your help

[chrisfont23]

I have 0 TDS. Before TDS I am at 67, which leads to hair algae in my water FWIW.

I believe adding a deionizer will get you to 0...am no expert on that tho.

[hazeen]

Well .. IF 67 will do algea problem, what will happen IF I use my tap water without RO then!!?

[chrisfont23]

Ummm...there's really no telling. I would imagine there are a few factors that went into my hair algae, including length of tank maturity and the limited numbers of CUC I had in the tank. But the fact I was using TAP water with a TDS at half of what you currently have doesn't make it likely you will avoid an algae bloom.

I change out my DI cartridge at 1 PPM.... my filters every 9 months.

HTH

[hazeen]

something is wrong then, if we go back to leebca's post regarding the source of the water:

The TDS of RO/DI water should be below 10. ppm -- all dependent upon the membrane and DI system. Rarely does this water make it below 1 ppb. Besides monitoring this feature to verify the RO/DI treatment system is working properly, the aquarist may wish to test for small ions (iron, copper, etc.) in the water to verify these are not finding their way into the aquarium.

mine produced a water with 150ppm, i have been told that the TDS depends on the tap water that I have, however, I will check with the supplier if they have got any membrane to get less TDS..

[Reefing Madness]

something is wrong then, if we go back to leebca's post regarding the source of the water:

The TDS of RO/DI water should be below 10. ppm -- all dependent upon the membrane and DI system. Rarely does this water make it below 1 ppb. Besides monitoring this feature to verify the RO/DI treatment system is working properly, the aquarist may wish to test for small ions (iron, copper, etc.) in the water to verify these are not finding their way into the aquarium.

mine produced a water with 150ppm, i have been told that the TDS depends on the tap water that I have, however, I will check with the supplier if they have got any membrane to get less TDS..

The last of the TDS is removed by the DI canister. If you are not getting to 0 then add another DI canister, that will take you down to 0. Unless your membrane is really old, its doing its job. Some just can't get it down using 1 DI filter. And I don't know where that posting regarding the water source came from, but my RO/DI TDS is 0 with one DI canister and 160gpd RO Membrane. If your really having issues, use 2 RO membranes and 2 DI canisters.

[chrisfont23]

Rarely does this water make it below 1 ppb.

[Reefing Madness]

We both can't be crazy, can we?

[chrisfont23]

I am getting ready to upgrade to a 90...so I will be shelling out some cash and wanted to be sure I am "starting right" - so this was one of those posts I triple checked myself on.

[chrisfont23]

We both can't be crazy, can we?

Anything is possible

[hazeen]

Thanks for sharing

Does the RO system that i have already RO/DI? or just RO?

it has 5 stages

1- 5Micron Sediment Filter
2- granular Activated carbon filter
3- 1Micron Sediment filter
4- RO Membrane
5- Post Carbon filter

CORRECTION

The TDS for the tap water i have is 1450ppm... woow !! poor isn't it? or HARD water?

The TDS after RO i'm getting is 150ppm, the water that we dring came in a bottle is 125ppm

Thanks

[Reefing Madness]

DI canister is the last canister filter the water goes through. You do not have one shown on your list.
AQUARIUM CORAL REEF RO +2 DI 150G REVERSE OSMOSIS PURE WATER PURIFICATION SYSTEM | eBay
The 2 canister on the very top of this unit are DI.

http://www.ebay.com/itm/DM-1-Inline-...item2ea47c795e

http://www.ebay.com/itm/Heavy-Duty-D...item5188c43a00

[chrisfont23]

The TDS for the tap water i have is 1450ppm... woow !! poor isn't it? or HARD water?

The TDS after RO i'm getting is 150ppm, the water that we dring came in a bottle is 125ppm

Thanks

Figure:

0-75 is ppm 'soft' water
75-100 ppm is moderately hard
150-300 ppm is hard water
300+ very hard

I would consider 1450 ppm "polluted"

[hazeen]

Well ..What can I say about our water!!

this is what exactly I bought
Delhi India

what do you think?

[chrisfont23]

Well ..What can I say about our water!!

this is what exactly I bought
Delhi India

what do you think?

Personally, I think you have a giant uphill battle ahead of you. It might be easier to keep a cat.

Good luck.

[hazeen]

hehe thanks

i will not give up, i have been keeping a planted tank with a same water for more than 10 years, things like this will not stop me.. i'm ready to fight..

[leebca]

There is a chance you don't have what you think you have. That is, the membrane is perhaps not right. There are different membranes for different applications.

The RO membrane is 'fixed' with certain sized pores. So regardless of the quality of the water ahead of it, it should only allow those certain sized chemicals through.

Then maybe there is no membrane? The quality of the water through a deionized system is very much dependent on the quality of the water going into it, and your supplier's answer would make sense if your system was deionized only, without RO.

The proper system handling North American water in general should yield below 10 ppm. I treat my water for my FOWLR and the TDS I use is below 6 ppm most of the time -- sometimes as low as 3 ppm. But that was a conscious choice of membrane and DI, since a FOWLR system doesn't require high purity water (like perhaps a reef system with more sensitive life forms).

[chrisfont23]

hehe thanks

i will not give up, i have been keeping a planted tank with a same water for more than 10 years, things like this will not stop me.. i'm ready to fight..

Best of luck and we're here to help. Keep in mind...some of those planted tanks do better w/ heavier nitrates and such anyway...not sure what you have in your water there, but it may be beneficial nonetheless.

[hazeen]

Hi

I have no luck today to call the supplier for few Q.

However, IF the minimum TDS that RO system can get is 150ppm, can I connect a water softener after the RO System? Would this help to get zero TDS?

Thanks

[leebca]

First keep in mind that zero is not likely. With a testing device that measures in ppm, it may read "0" but it just means it can't detect what is there. Still, that is good. The scientist in me comes out and has to bring this point up -- an absolute zero is impossible with the water purification processes hobbyists use.

After the RO, a DI treatment is usual. But you'll face issues with whether or not the resin in the DI unit is proper. Still, it should reduce the TDS further. The reduction will depend on what the 150ppm is made up of in the way of ions. A DI resin unit will remove charged chemicals/ions: positive ions, negative ions, or if a mixed bed, with remove both. If the 150ppm contains some 'neutral' organic molecules, the resin may not affect that. Without knowing what is left from the RO unit, using a mixed resin bed for your DI unit should reduce the ppm significantly. Don't forget that the resin does add something back into the water. You want to use a resin that adds either hydroxyl (-OH) or hydrogen (H+) ions back into the water (or both if it is a mixed bed).

Adding a DI unit after the RO unit will improve the water quality almost all the time.