Is RO water necessary in a reef tank?

[soeminpaing]

it’s like a person crossing the road and another crossing the road with eyes closed. Literally you are taking a chance. As per Murphy’s law, most try to avoid any failure since there are a lot of areas where a reef tank may fail like electricity, heating, disease and human errors. Also tap water tends to vary season to season and you might never know what’s in it.

 

[Blacktip]

RO water is a must for stability and consistency. Sure, one can do it without RO water, but it is going to be a constant battle.

 

[K-pow]

Well I switched to RO/DI water today. I hope to see a difference in the future

 

[Thub]

I'd recommend grabbing a TDS meter to find out what your tap runs at. If your water is like mine (basically liquid gravel), and if you have a fairly aggressive water change schedule, switching straight to RODI might cause some significant swings in minerals.

 

[K-pow]

I’m going to switch over time. I’m in no rush. I like to take time so I don’t shock the tank. I did add some supplements as well into the water before adding. But only partial doses. Do you think that is okay?

 

[GoldeneyeRet]

I think RODI for source water is extremely important. I would not keep a reef without it.

 

[vetteguy53081]

You are reading this very post from a person who skipped the belief that RO is necessary. 3+ Years of various issues: algae, ph, clarity amongst other issues with coral mainly.
My wake up call was going on a week and a half vacation and having a local trusted Reefer tend to my tank.
Although i trusted him fully , i often wondered how tank was doing but couldn’t call him as I was in the Caribbean. I finally returned home , walked through the door and was shocked at how beautiful the tank looked.
I of course asked him if he did some magic as my tank looked its best. He said nothing other than it got low and he brought 6 gals of RO from his house and added it to my tank. It was not only then that I knew that it was time to buy RO water, but to use RO only. Yes- I continued to BUY RO water for over a year then last year bought a used Ro unit. I have been able to keep meaty and SPS coral since.
I just upgraded my RO unit and purchased another but happy with upgrade so selling the other new one in market place.
BOTTOM LINE: lesson learned from doubt and resistance and Yes RO necessary if you want a completely successful sustainable tank system

 

[Silly clownfish]

I am always amazed in these threads to see that people say that they wouldn’t use their tap water in their tanks because they don’t know what is in it. But they drink, cook, and bathe in this same water themselves. If you have municipal water, you should be able to get a comprehensive water analysis report from your supplier. It might even be on their website, or you may need to call. Unless you live in Flint they should be happy to share.

If you have a well, like I do, you really need to take responsibility for knowing what is coming out of it. This can impact your health, not just your tank’s. Look up certified labs in your area and get a full analysis- not the basic one that just checks things you already have a test kit for plus coliforms - the one that cost a couple hundred dollars and checks for several pages worth of dipoly-something-ene. dry cleaning solvent , etc. Your county dept of health may be able to recommend labs and tell you of any groundwater contaminant plumes in your area. They will be happy that you asked.

I have been reefkeeping since the 90’s using straight tap, RO, and RO/DI over the years. My tap water is excellent for drinking. Water gets bottled for sale from my watershed. I originally started filtering to try to address a hair algae problem. That was about 29 years ago and I don’t remember how much it really helped. Currently I run just RO as I go through DI resin in about 50 gallons since I don’t aerate before filtering. My DT was beautiful until a dosing pump error a few months ago (that would never have happened with manual dosing). I have had fish, corals, and inverts survive 15-20+ years in that tank.

Sorry for the lecture, but having been a professional water resources engineer for over 25 years, its kinda my thing.

 

[Thub]

I am always amazed in these threads to see that people say that they wouldn’t use their tap water in their tanks because they don’t know what is in it. But they drink, cook, and bathe in this same water themselves. If you have municipal water, you should be able to get a comprehensive water analysis report from your supplier. It might even be on their website, or you may need to call. Unless you live in Flint they should be happy to share.

If you have a well, like I do, you really need to take responsibility for knowing what is coming out of it. This can impact your health, not just your tank’s. Look up certified labs in your area and get a full analysis- not the basic one that just checks things you already have a test kit for plus coliforms - the one that cost a couple hundred dollars and checks for several pages worth of dipoly-something-ene. dry cleaning solvent , etc. Your county dept of health may be able to recommend labs and tell you of any groundwater contaminant plumes in your area. They will be happy that you asked.

I have been reefkeeping since the 90’s using straight tap, RO, and RO/DI over the years. My tap water is excellent for drinking. Water gets bottled for sale from my watershed. I originally started filtering to try to address a hair algae problem. That was about 29 years ago and I don’t remember how much it really helped. Currently I run just RO as I go through DI resin in about 50 gallons since I don’t aerate before filtering. My DT was beautiful until a dosing pump error a few months ago (that would never have happened with manual dosing). I have had fish, corals, and inverts survive 15-20+ years in that tank.

Sorry for the lecture, but having been a professional water resources engineer for over 25 years, its kinda my thing.

It sounds to me like you've just got great tap water. My tap comes out at 325-500 ppm TDS, and depending on time of year, up to 3ppm (not 0.3) phosphate. Is 0 TDS water necessary? No. Can people with my tap water use straight tap water? Probably not.

 

[SDK]

I am always amazed in these threads to see that people say that they wouldn’t use their tap water in their tanks because they don’t know what is in it. But they drink, cook, and bathe in this same water themselves. If you have municipal water, you should be able to get a comprehensive water analysis report from your supplier. It might even be on their website, or you may need to call. Unless you live in Flint they should be happy to share.

If you have a well, like I do, you really need to take responsibility for knowing what is coming out of it. This can impact your health, not just your tank’s. Look up certified labs in your area and get a full analysis- not the basic one that just checks things you already have a test kit for plus coliforms - the one that cost a couple hundred dollars and checks for several pages worth of dipoly-something-ene. dry cleaning solvent , etc. Your county dept of health may be able to recommend labs and tell you of any groundwater contaminant plumes in your area. They will be happy that you asked.

I have been reefkeeping since the 90’s using straight tap, RO, and RO/DI over the years. My tap water is excellent for drinking. Water gets bottled for sale from my watershed. I originally started filtering to try to address a hair algae problem. That was about 29 years ago and I don’t remember how much it really helped. Currently I run just RO as I go through DI resin in about 50 gallons since I don’t aerate before filtering. My DT was beautiful until a dosing pump error a few months ago (that would never have happened with manual dosing). I have had fish, corals, and inverts survive 15-20+ years in that tank.

Sorry for the lecture, but having been a professional water resources engineer for over 25 years, its kinda my thing.

Well said, but this is why absolute statements in either direction don't tell the whole story.

I have been keeping saltwater tanks since the late 1970's, and in my area, always struggled with nutrients. I finally laid out what was an insane amount of money in 1980's prices for an RO/DI unit and never looked back.

We are in a golden age compared to then, where you can buy a basic unit from BRS for under $150. For the vast majority of reef keepers, this is a no brainer of an investment.

The water where I live now is even worse, and I don't drink it. We have a water cooler in the kitchen.

 

[Qasimja]

when i started reefing in the late early 2000s i used tap water could not afford an rodi unit and i had very successful reef tanks but as the years went on and the rodi units became cheaper and cheaper it was just easier to buy one and filter the water and not have to worry about whats in it ive been using rodi since maybe 2008-09

 

[Indytraveler83]

I'm sure I'm entirely uneducated in this matter, but something I don't entirely understand:

TDS is dissolved solids, and everyone here strives for TDS of zero. But isn't calcium and magnesium technically TDS?

Our tap water has extremely high calcium in it (around 440 ppm) magnesium levels high enough I never have to dose, and alk and pH levels almost exactly matching saltwater.

I'll admit I use tap water (don't flame me) because it seems counterintuitive to spend money on RODI equipment, remove all of that stuff, then dose it back in again. As it is, I only dose every few weeks to keep alk up, and my parameters are dead stable.

Reefers I talk to in the area spend tons of money replacing RODI media because the calci clogs it up fast, then dose like crazy and buy tridents and things to achieve the same paremeter stability I already have.

I'll admit my water isn't perfect, and I'm sure there are things in there I don't want, but isn't stability the single most important factor?

 

[Silly clownfish]

I'm sure I'm entirely uneducated in this matter, but something I don't entirely understand:

TDS is dissolved solids, and everyone here strives for TDS of zero. But isn't calcium and magnesium technically TDS?

Our tap water has extremely high calcium in it (around 440 ppm) magnesium levels high enough I never have to dose, and alk and pH levels almost exactly matching saltwater.

I'll admit I use tap water (don't flame me) because it seems counterintuitive to spend money on RODI equipment, remove all of that stuff, then dose it back in again. As it is, I only dose every few weeks to keep alk up, and my parameters are dead stable.

Reefers I talk to in the area spend tons of money replacing RODI media because the calci clogs it up fast, then dose like crazy and buy tridents and things to achieve the same paremeter stability I already have.

I'll admit my water isn't perfect, and I'm sure there are things in there I don't want, but isn't stability the single most important factor?

correct, high TDS doesn’t necessarily equal bad. Knowing what your tap water contains and how your tank performs with it is the key. There is no one size fits all solution.

and knowing what is in it is important for you as well as your fish.

 

[Qasimja]

another thing i kinda find funny that ive seen is people who say 'you should only ever use rodi otherwise you will have all kinds of algae problems' but new tanks will go through tank uglies whether you use rodi or not

 

[TheShrimpNibbler]

I used tap for quite a while, and although it was working, things just didn’t look good. Algae was everywhere and fish for parasites a lot more easily. I’ve switched to distilled, and I’ve noticed a huge difference. I think I’m gonna invest in an RODI, I just tried distilled first to make sure it was worth the money. It is.

 

[Sleepydoc]

I am always amazed in these threads to see that people say that they wouldn’t use their tap water in their tanks because they don’t know what is in it. But they drink, cook, and bathe in this same water themselves.

...

Sorry for the lecture, but having been a professional water resources engineer for over 25 years, its kinda my thing.

If you're a professional water resources engineer than you should know how ludicrous this statement is. I'll give one example and leave it at that: Chlorine. You swim in and drink chlorinated water and suffer no effects, yet your tank would die with it.

I'm sure I'm entirely uneducated in this matter, but something I don't entirely understand:

TDS is dissolved solids, and everyone here strives for TDS of zero. But isn't calcium and magnesium technically TDS?

Our tap water has extremely high calcium in it (around 440 ppm) magnesium levels high enough I never have to dose, and alk and pH levels almost exactly matching saltwater.

I'll admit I use tap water (don't flame me) because it seems counterintuitive to spend money on RODI equipment, remove all of that stuff, then dose it back in again. As it is, I only dose every few weeks to keep alk up, and my parameters are dead stable.

Reefers I talk to in the area spend tons of money replacing RODI media because the calci clogs it up fast, then dose like crazy and buy tridents and things to achieve the same paremeter stability I already have.

I'll admit my water isn't perfect, and I'm sure there are things in there I don't want, but isn't stability the single most important factor?

Yes, Ca and Mg are TDS. as are Fe, Cl, Na, Cl, Cu...

The point is a TDS meter doesn't tell you what the solids are, just that they are there. We have very hard water with a lot of Ca and Mg in it. If I could take all the undesirable stuff out and leave the Ca and Mg in I would, but I can't. By making DI water then adding salt mix I control the composition of the water and know what's in it. That's the critical difference.

another thing i kinda find funny that ive seen is people who say 'you should only ever use rodi otherwise you will have all kinds of algae problems' but new tanks will go through tank uglies whether you use rodi or not

The 'ugly' phase of starting a tank is just that - a phase that tanks go through as the biome gets established. Eventually, everything settles out to an equilibrium. If you are adding nitrates or phosphates from your water supply, you run the problem of settling out at a different, undesirable equilibrium.


Many people have said it above, and I'll say it, too. there are no absolutes. One cannot universally say 'tap water is bad.' any more than one can say 'tap water is good.' Using RO/DI water changes the water quality from an unknown variable to a known one, simple as that.

 

[Cory]

All will be fine until your city cleans the pipes and potassium permanganate comes through. Or they decide to add phosphate to control lead. Or they switch from chlorine to chloramines. Or your cities pressure jumps and your home pipes shake and release a ton of nasty stuck to your pipes. Thats why i filter my tap water.

 

[Rybren]

All.will be fine until your city cleans the pipes and potassium permanganate comes through. Or they decide to add phosphate to control lead. Or they switch from chlorine to chloramines. Or your cities pressure jumps and your home pipes shake and release a ton of nasty stuck to yojr pipes. Thats why i filter my tap water.

This. I always ran my FW tanks with tapwater and for the first few years of my salty life, I also used tapwater. The city provides very detailed water analysis reports and our water is very good - aside from choramines, which can easily be treated with Prime or a similar product.

However, one day the city treated the water for something. I don't recall what the product was, but more than 20 people in our small club had their tanks wiped out by it. I was one of the fortunate ones who hadn't used any of the treated water, but the event scared me enough to go out and get a RODI unit.

 

[Paul B]

Or they decide to add phosphate to control lead. Or they switch from chlorine to chloramines.

For the first ten or so years of the life of my reef I lived in the New York City limits and New York City has some of the best tap water in the nation. The cobblestone water tunels are almost 150 years old and they are 900 feet below the city. At one time they were the longest tunels in the world spaning 22 miles from upstate resivours.

Having said that, my tank was runing perfectly. Then one day I did a water change and immediately my fish started to jump out of the tank and others just croaked.

I didn't know what to do, we didn't have test kits then.

I called my water company and they said they added Zinc Orthophosphate to the water supply to control corrosion in the pipes and that it is actually good for "people".

Maybe it is, but not for fish and in their defense, they are not paid to keep fish safe, only people.

But I lost almost all my fish in 5 minutes. They must have added the stuff right outside my house. ;Bucktooth

 

[serez]

I do not use RODI water, although I have in tanks past and I am quite proud of my tank. It just so happens my tap water parameters are very well suited for a salt tank, terrible for a freshwater plant tank (epic fail).

Having said that, my tank is too far for me to get to my basement to my old RO system (or I'm too lazy, hmmm) but in a perfect world I would use RODI water, and I recommend to anyone that asks that they do the same. It is the way to go if you don't live by a nice clean ocean to pull from!

Hey there, what’s your tap water perimeters? What’s the TDS reading if u have it? I’m new to reefing and setting up my first tank. I got a RO system and produced water with 90 tds. People are telling me I want zero tds and nothing else. Can u please give me some advice?