How vigilant are you when it comes to the TDS of your RODI water?

[flyfisher2]

I had given up a couple years ago because I couldn't keep a coral alive here to save my life. When I lived up north I did ok. I spoke to a neighbor in my development who was having the same problem and also gave up reefing.We both attributed our failures to water quality as we are in a developing community and the TDS fluctuated between 150 and 250. I finally decided to come back this year and I've been diligent about the water quality and chasing the 0 TDS. I'm not only keeping just about everything alive I'm seeing growth! It's not cheap to change out DI resin almost monthly but I can see the results. As it stands I just received a new Membrane (75 GPD) and the manual flush valve from BRS to match the membrane. Previously I was using the flush valve for a 100 GPD and upon reading more about it I discovered that I needed to match the membrane. I hope this will increase the rejection rate coming from the membrane and in so doing give me a little more time between the DI changes?

 

[Biglew11]

I make sure i have otds coming out of my unit, but I hardly ever check the tds of the water after its in my brute storage container. i have 4 tds sensors on my unit, tds of in coming water is usually around 145. tds after two membranes in water saver setup hovers around 3-4, 3 stages of di cation anion and mixed bed with sensor between 2nd and 3rd di, and a sensor at the output of the 3rd di as it's sent to the brute. i change anion when i get 1tds right after it. i change the mixed bed when it gets about 3/4 used.

 

[Doctorgori]

Our municipality water is river source and varies between 400 - 800 ppm, it terrible. If my system still gets under 10 ppm I’m still ok with it

 

[Laith]

As soon as I see a reading of 1 on the output of the first DI canister (I use two) I swap them and refill the last one with fresh DI resin.

I like this setup as even if the reading of 1 on the output of the first DI canister has been there for X liters of water being made, I know the second canister will ensure that water being used for the tank is always 0 TDS. ;Happy

 

[Bruce60]

What’s TDS I don’t make salt water I use all ocean water 100%,,, does it have TDS ???? I’m

Nice, but how do you replace evaporated water, which leaves the salt behind?

 

[Bruce60]

I prefer to use RO/DI water with a TDS of 0. I don't freak out if it goes up to 1 or 2. I just know that I have to change the DI resin. But I also rinse everything for the tank in RO water (TDS typically in the 5-8 range), so I may be a bit on the extreme end.

 

[Timfish]

I never worried about it then I saw some discusion on the local forum rough;ly 10 years ago and started tracking it in my tanks. After about a year I stopped as it seemed pretty much a waste of time.

 

[Paulie069]

Nice, but how do you replace evaporated water, which leaves the salt behind?

Boiled spring water

 

[Bruce60]

Boiled spring water

Interesting. Why do you boil it? I would think that if it is safe to drink then boiling it won't make it any better for your fish and corals.

 

[K7BMG]

This may be an ignorant question.

But testing tank water for TDS?
The RO/DI units remove salts, silicates, chlorines, ECT.
When you add preferred known salts to the RO/DI water of course the TDS will rise.
So I don't understand the point.

 

[Paulie069]

Interesting. Why do you boil it? I would think that if it is safe to drink then boiling it won't make it any better for your fish and corals.

Just for peace of mind

 

[Laith]

This may be an ignorant question.

But testing tank water for TDS?
The RO/DI units remove salts, silicates, chlorines, ECT.
When you add preferred known salts to the RO/DI water of course the TDS will rise.
So I don't understand the point.

Not tank water... the water coming out of your RO/DI unit.

 

[K7BMG]

Not tank water... the water coming out of your RO/DI unit.

Right but I will have to go back but I thought I read one post that said they tested tank water for TDS.
I was like what?

 

[Buckeye Hydro]

My faucet water TDS varies in the summer and winter. In the winter it is 3. In the summer it is max 8. Do I need a RO unit for my coral? I currently have a BRS 6 stage that always produces 0 TDS.

The water out of the faucet states terrible.. the RO unit is just as much for us as it is for the coral.

I suspect those TDS readings from your tap water are not correct.

 

[Buckeye Hydro]

Prob. aware of this but in case not you can pick up a cheap hand held one from Amazon for under $20.

Or even from a sponsor that supports reef2reef!

TDS3 Handheld Meter

At Buckeye Hydro we specialize in providing the highest quality water filtration systems and accessories for every potential need.

www.buckeyehydro.com

 

[josephxsxn]

When my RODI output hits 1 I'll change the DI out. Sometimes the water I collect was output at 1 TDS before I get to it overnight because I do around 50-150 gallons of RODI at once so it's running while I sleep then.

 

[Sleepydoc]

I dib not read all of this . If zero is the magic number can anyone please tell me what is wrong with the water coming out when it hit's 1 tds . I have a 1000 gpd unit from Aqua Fx . I have high nitrates and po4 in the water coming into the house . The unit has been up and running over a year with the same carbon and di resin that I purchased with the unit. Tested water today zero nitrates and zero po4 . Also ati test passed with flying colors . I am thinking you are wasting your money. I run the carbon a di that Aqua fx recommends .

If you are using an RO/DI filter, you should be keeping it at 0.

The problem with letting it creep up is that different contaminants have differing affinities for the resin, so the TDS of 3 isn’t just 3% of your baseline TDS of 100, what happens when the resin is depleted is the elements of higher affinity bind the resin and displace the elements of lower affinity, so you may actually end up with higher concentrations of more undesirable contaminants, and ultimately, you don’t know exactly what’s in your water. If you are concerned enough to use an RO/DI filter, why wouldn’t you be concerned enough to change the resin when it’s depleted?

 

[Sleepydoc]

Will probably catch heck for this but where is the scientific proof? As being somewhat new I will buy into needing to remove things like chlorine etc. from city water and certain metals from well water but has any of you ever tested the ocean in a reef with your equipment? We pollute enough that I am guessing you will test positive for TDS as well as other chemicals. 30 years ago I had an FO salt tank with an HOB, I distilled water for my tank because it was city water and there were no small scale RODI systems available to the casual hobbyist. My yellow tang, box fish and seahorses did just fine for a year and a half including a move from one apartment to another. What did the tank in was not water quality, it was temperature when my apartment A/C unit died during a heat wave.

First, reef tanks have higher water quality needs than fish only tanks. There are many people who successfully use well water or tap water for their tanks. There are also many people who do so and have constant problems. The problem is the water coming out of your tap is considered safe for human consumption (unless you live in Flint, MI.) What is safe for humans is not necessarily safe for fish or invertebrates. Chlorine is a prime example but there are many others. Copper actually helps prevent bacterial growth but if you have copper pipes, you could well be getting copper in your system that will harm the invertebrates.

The other issue is the municipalities are under no obligation to inform you of changes that will affect your livestock. They may decide to switch from chlorine to chloramine, or they may drill a new well so the water has different contaminants. If your city takes water from a river, there may be seasonal changes, etc.

The reason many people use RO/DI water is because it takes the guess work out - unlike your tap, you know what is coming out of the RO/DI filter. If you are only trying to keep fish treated tap water may be fine. If you are trying to keep corals it’s another Story.

 

[Rudefish]

I have TDS reading of 112 in from my well water and after going through the cartridge and membrane it then register 2. Once it goes through the resin it is then 0. Resin is changed only when the color completely changes. TDS continues to read zero until color completely changes without fail. Nothing else is changed until the meter, after the membrane, reads more than 2.

 

[Rudefish]

i should have added that is a lot less expense to refill the resin cartridge than it is to always buying new ones.