TDS Question...

[cbianco]

Hello

As some of yall know I purchase my water from the Wal-Mart vernding machines, either Culligan or the penguin machine (I forget the name).

Recently, I saw that the Culligan machine was checked and they listed a TDS of 9ppm. Cullingan has never listed a number for their TDS measurement so this was the first time I saw this.

Can someone tell me if a TDS measurement of 9ppm is any good?

What is the range in ppm that is acceptable to use in our tank?

Thanks in advance.

Christopher

[Ed]

I would say 9ppm is pretty good for RO. My unit runs 11ppm after RO and before DI. DI can get it to 0ppm.

HTH.

-Ed

[cbianco]

I would say 9ppm is pretty good for RO.

Can 9ppm still cause problems in your tank as far as unwanted algae growth goes?


My unit runs 11ppm after RO and before DI. DI can get it to 0ppm.

The Culligan unit claims that they are running DI as well as the RO unit.

Should we be concerned that the water is not testing at 0ppm like your unit?

Christopher

[matt]

9 is okay. I change my D.I. when it gets to 10, but anything under 25 is probably pretty good water. My tap water is around 250-300, and most R.O. membranes have about a 90% rejection rate, so coming out of my R.O. it's around 20. The really important thing is to get all the chlorine out, and the carbon block does that.

But, it's entirely possible that if you took a sample of the water from the machine it would read much higher than 9. I'd be interested in that if you can borrow or buy ($30 or so) a TDS meter.

[Ed]

I agree. 9 is Ok. Couldn't hurt to test the water and double check what was posted either.

[cbianco]

9 is okay.

Good to hear! :)


But, it's entirely possible that if you took a sample of the water from the machine it would read much higher than 9. I'd be interested in that if you can borrow or buy ($30 or so) a TDS meter.

You wouldn't be suggesting that somebody is lying to make a buck now would you? :roll :lol

I am sure that the machine is not kept up as well as yall's home RO/DI systems!

The reason that I am seeking advice on this subject is because I seem to have an algae problem that I cannot shake. It is driving me nuts!

Christopher

[hammondegge]

"The Culligan unit claims that they are running DI as well as the RO unit. "

for drinking water? i have been told that DI is too caustic for drinking water. should only be RO

[cbianco]

Robert

I could be wrong but I am almost fairly certain they are running DI. I will be sure to make note of it the next time I go to the store.

Christopher

[GaryP]

The question is whether the 9 ppm is before or after they service it. If its 9 ppm after they service it, what the heck is it before they service it and when are you getting your water? That's the problem with those machines. You never know if you are getting your water at the beginning or end of the service cycle.

[Richard]

If you have the test kits you might check for nitrate and phosphate over a period of time to make sure that the water is not the source of your algae problem.

Even a higher tds isn't always bad since it could just be carbonates. For example I usually use 50% di water and 50% tap water (well water) for my water changes. My corals seem to appreciate the extra carbonates and since I do not have a problem with phosphate or nitrate in my well water it has not caused any algae problems.

[JimD]

Anything above .3 ppm is unacceptable, if youre questioning it, no doubt its not right.

[alton]

DI takes out the benficial minerals that our bodies need to survive, I got this information from a Kent engineer when I asked him the question of using DI for drinking water. My TDS after the RO is 3 to 4.

[GaryP]

According to SAWS, nitrates in city water are between .1 & 2.5 ppm with an average of 1.8 ppm. The maximum allowed concentration by law is 10 ppm. They do not have any data on phosphates.

The average TDS is 317 ppm.

For those of you interested, here is the 2006 drinking water quality report from SAWS.

http://www.saws.org/our_water/waterquality/Report/2006_WaterQualityReport.pdf

[cbianco]

The question is whether the 9 ppm is before or after they service it.

Appearently this is the TDS number after their servicing.


If you have the test kits you might check for nitrate and phosphate over a period of time to make sure that the water is not the source of your algae problem.

Even a higher tds isn't always bad since it could just be carbonates...

I don't normally check the water that I purchase. I don't have a phosphate test kit but I can see that it will be necessary to purchase one.

You say that TDS is just carbonates, I was under the impression that TDS is a measurement of all the "junk" in the water (i.e. nitrates, phosphates, etc.), interesting to know.


Anything above .3 ppm is unacceptable, if youre questioning it, no doubt its not right.

Jim, I assume that you are talking about phosphate here. Correct me if I am wrong.


You're thinking of Distilled maybe? Lots of drinking water is RO'd and distilled, but DeIonized makes it taste funny.

You may be write about me mixing it up :) I promise to check the next time I am at the store, lol.

Christopher

[cbianco]

Ignore :)

[cbianco]

Ignore :)

[GaryP]

No, TDS is "Total dissolved Solids." Carbonates and Calcium are a big part of the total, but other stuff like sodium & chloride are in there too. I wouldn't go buy a phosphate test kit just for testig your source water. Take a sample to the LFS and have them run it for you.

Whether there is phosphates in your source water or not is a non-issue in my opinion. If there is phosphates in the water, its at a level that is a drop in the bucket compared to the amount you dump into your tank in the form of food every day.

Just to give you some idea, you are adding about .3 grams of phosphate for every ounce of food (dry weight) you use. If you do the math that means that you are adding .6 ppm of phosphate in a system that contains 100 gal. of water. That's a lot of phosphate.

In order for you to keep a low phosphate level in your water, you would need to export an equivalent amount of phoshate every day. By export, I mean skimming, mechanical filtration, siphoning, chemical absorption, and conversion to biomass (fish, inverts, and macro). If you exports are less then the amount you add, you will eventually start to build up phosphates and end up with a algae bloom.

Phoisphates in natural waters are usually very low unless they are polluted with fertilizers or waste water. I'm not saying that there may not be some phosphate in our waters, but if you address the phosphates entering the system from food, then you will handle this small quantity as well.

One more thing. I AM NOT advocating cutting back on the feeding of your tanks. Most of us don't feed enough, or as frequently, as we should as it is now. The solution to water quality issues is not starving your tank. Rather, take a logical approach to water quality management and go about it that way. The problem is not fish food. The problem is how you handle the waste that results from the fish food.

[GaryP]

The question of how much phosphate is in tap water kept bugging me so I did some more research.

I found an Edwards Aquifer Report that had had water analysis data in it. They reported a typical range of 0-.03 ppm ortho phosphate, with a maximum reported concentration of .104 ppm. This data was from 2004.

[GaryP]

[quote=GaryP]That's straight aquifer water though right? That doesn't necessarily reflect what's coming out of the tap.

All the city does is add chlorine and flouride to aquifer water and send it down the pipe. They wouldn't add phosphate.

[cbianco]

Whether there is phosphates in your source water or not is a non-issue in my opinion. If there is phosphates in the water, its at a level that is a drop in the bucket compared to the amount you dump into your tank in the form of food every day.

I don't feed my tank at all! I have nothing to feed. If I could atleast restrict the amount of phosphates in my tank through water changes it would give me piece of mind.

If its not phosphates I have no idea what is causing my algae. Nothing else goes into the tank except water. :)

Christopher

[GaryP]

I have a theory.

Not feeding results in nutrient poor water. Nutrient poor water results in die off. Die off results in decay. Decay results in phosphates. Phosphates result in algae. Algae results in this thread. This thread results in this theory. :)

[GaryP]

I think you skipped a few steps there. Try to stay with me Joshua...

[GaryP]

Actually, its not phophates that are the problem. You drink tons of it in a soda. Nitrites and arsenic are the big problems in tap water in the US. Not in this area, but in other areas they are an issue. They're using phosban in some parts of the US to remove arsenic. They had some big issue in California with waste from dairies contaminating the ground water. The waste resulted in elevated levels of nitrite. Nitrite in human binds to hemoglobin, like cyanide and carbon monoxide does and prevents oxygen from being exchanged in the blood. There was some death of children attributed to this. A lot of dairymen from California moved to Texas. Go figure. They're clustered up around Stephenville now.

[cbianco]

I have a theory.

Not feeding results in nutrient poor water. Nutrient poor water results in die off. Die off results in decay. Decay results in phosphates. Phosphates result in algae. Algae results in this thread. This thread results in this theory. :)

My head is spinning! :blink :)

Christopher

[GaryP]

Basically, everything needs food. If your tank is sitting there with just live rock and sand and no nutrients being putting into the tank, stuff is going to die. When it dies, it decays and produces a lot an excess nutrients that leads to the algae bloom. These same critters that are dieing may be the same ones that were absorbing your excess nutrients when the tank was being fed and they just release it back to the water. In other words your tank is cycling again. Without some sort of constant input of nutrients, it will just continue to cycle and go through boom and bloom cycles. When the food from this die off is consumed, stuff will start to die again and the cycle will just start over again. I'm guessing that you're probably not doing water changes and other maintenance type stuff while the tank is empty, right? This probably increases the cycling issue.

The question is, is your head spinning from my post or the shooters you did last night?