Tap Water or RODI water?

[IndianaReef]

So I have done some research, and where I live the chlorine level in my water is 0.85mg/l (<1ppm), and 56 - 73 (mg CaCO3/L) . In addition to treating my tap water with a water conditioner, what is the real danger in using tap water instead of rodi. If i am being extremely silly here please tell me, and explain what the benefits/need of RODI is, if treatment of tap water is an option. Please also explain why this is a bigger deal when discussing saltwater tanks and not freshwater (I have no coral yet and will definitely use rodi when i get there).

 

[Saaqib_Ansari]

So I have done some research, and where I live the chlorine level in my water is 0.85mg/l (<1ppm), and 56 - 73 (mg CaCO3/L) . In addition to treating my tap water with a water conditioner, what is the real danger in using tap water instead of rodi. If i am being extremely silly here please tell me, and explain what the benefits/need of RODI is, if treatment of tap water is an option. Please also explain why this is a bigger deal when discussing saltwater tanks and not freshwater (I have no coral yet and will definitely use rodi when i get there).

There are a lot more things in tap water which is made for us - fluorine, copper etc all things which aren’t needed in a salt water tank. Honestly I ran my tank on tap water with a conditioner for 1 year and I did face a lot of algae problems - fish seemed fine coral were ok. I’ve started using RODI water now and can honestly say everything looks better - fish seem healthier coral is growing.

 

[blasterman]

Tap is a big issue with coral. Its not a big issue with fish provided you deal with potential chlorine issues. Just get a good algae scraper if your city water is like mine.

Tap is a problem with freshwater. Actually worse. The pH of most municipal water is high due to dissolved minerals and this is bad for pH sensitive tetra species, etc.

 

[Radicalrob1982]

So I have done some research, and where I live the chlorine level in my water is 0.85mg/l (<1ppm), and 56 - 73 (mg CaCO3/L) . In addition to treating my tap water with a water conditioner, what is the real danger in using tap water instead of rodi. If i am being extremely silly here please tell me, and explain what the benefits/need of RODI is, if treatment of tap water is an option. Please also explain why this is a bigger deal when discussing saltwater tanks and not freshwater (I have no coral yet and will definitely use rodi when i get there).

You can do it and things will probably turn out ok. But Ive done it in the past and wish I never did. It will takes months for the affects to wear off after you decide to use all ro water. You can buy a small 50gallon per day ro unit fairly cheap. And its worth every penny. Youre gonna end up with undesireable algae with more nitrates and phosphates.

LIke I said its not going to be the end of the world if you use tap water. But it can and will cause problems down the road. Ive noticed such a huge difference now that Ive been using ro water for the last 4 months. I over all have less nitrates and phosphates and barely have to clean my glass. Before I was scraping it daily. Now maybe 2 times a week.

The majority of the time i used ro water. But then get lazy and use tap water for topping off and the odd time for a water change if I didnt want to wait for the water to be made. But now I use exclusively ro and things have never been better

 

[Radicalrob1982]

Tap is a big issue with coral. Its not a big issue with fish provided you deal with potential chlorine issues. Just get a good algae scraper if your city water is like mine.

Tap is a problem with freshwater. Actually worse. The pH of most municipal water is high due to dissolved minerals and this is bad for pH sensitive tetra species, etc.

I had the same problem with my old fw tank. Couldnt figure out for the life of me why my nitrates were climbing so high each week. I had to do two 50% water changes a week to keep nitrates at 10 to 20 ppm. And I wasnt overstocked.

Kept thinking to myself to have so much nitrate that means I had to have a large ammonia source. I tested my tap water with just an API ammonia test kit and "WOW" I was basically pulling nitrates out and putting ammonia back in.

 

[NCK]

The reality is, with the expense of this hobby, making RODI water is a minor cost compared to some of the others. (Especially for moderately sized tanks.)

As others have said, you can get by with tap in the right conditions, but honestly: once you amortize the cost of a decent RODI system over several years and thousands of gallons, the cost works out to pennies per gallon - even accounting for ongoing consumables like resin and the occasional membrane.

At the end of the day: it’s not worth the savings considering the battles you’ll fight. (I know your initial concern wasn’t about cost. Just my opinion.)

 

[IndianaReef]

Okay thanks everyone. When I can afford it I will get an RODI system. Cheers

 

[Rit6942]

Depends on the tap.......city water loaded with chlorine etc.......you want at least a good simple 2 stage sediment/carbon filter cleaning up the water and getting rid of the chemicals..........if you have a well setup(artisan,dug etc) then have the water tested to see how pure it runs. I had clients in past not need an rodi system due to fact their well water was so pure. If budget allows all thats needed is a 3 stage RO unit.......the DI polisher is really not needed except for the most extreme dirty tap water conditions. And most people do not need that final stage.

 

[PatW]

My tap water has 1 ppm nitrates and .3 ppm phosphates. Tap water potentially has significant levels of copper. Even low levels of copper can build up in the tank when used in an auto top off. And there are other nasties potentially in tap water: insecticides, herbicides, heavy metals, drugs, petroleum derivatives and so on. RODI pretty much eliminates all that stuff.

 

[Dr. Dendrostein]

I had to go to the store for a little over a year to buy RO water for $0.35 a gallon. Then I bought my system to make water and corals loving it.

 

[vetteguy53081]

RO all the way.
Also, it really depends on the area where you live and how good the water is. Most water is safe to drink and take a bath in and therefore deemed safe, so you would think it would be safe for your aquarium inhabitants, and times it is. Many times there's phosphorous, arsenic, and other algae-promoting nutrients in the water that will result in algae blooms. You're trying to benefit your aquarium by removing waste, but with tap you're adding other forms of waste or nutrients that are going to promote algae growth.
For those reasons alone, I would always recommend using filtered water, reverse osmosis, a deionized filtered water, or even bottled distilled water in lieu of tap water. If you're in a bind and are out of RO water and your tank's a little bit low, you can use tap water. I would use a dechlorinating agent to remove the chlorines and chloramines. It's also better to let the water sit overnight so it has a chance to de-gas.

 

[I’m Batman]

what is the real danger in using tap water instead of rodi

If you can’t afford RO/DI, go purple cap Walmart distilled.... always rests 0TDS for me... if you have an extra couple bucks, get an actual RO/DI - 4 stage at least. I just spent 3 hours installing and flushing an additional 3 stages. It’s totally worth it. Never thought I’d get to this point but if you’re going to have corals and fish, why not provide them the best life support?

 

[Clownfish_Boy]

When I used treated tap water back in the day, I had a really bad problem with green hair algae. Tap water is high in phosphates, and God only knows what else. Also, when I was using treated tap water, I had a problem with haziness of newly made up water - with the RODI I get crystal clear water.

 

[Zoa_Fanatic]

So I have done some research, and where I live the chlorine level in my water is 0.85mg/l (<1ppm), and 56 - 73 (mg CaCO3/L) . In addition to treating my tap water with a water conditioner, what is the real danger in using tap water instead of rodi. If i am being extremely silly here please tell me, and explain what the benefits/need of RODI is, if treatment of tap water is an option. Please also explain why this is a bigger deal when discussing saltwater tanks and not freshwater (I have no coral yet and will definitely use rodi when i get there).

You’ve missed so many things about tap water that can cause you issues other than chlorine. I’m an environmental engineer. We put ungodly amounts of things into tap water in my state (I work for the government here) like fluoride to help provide better water quality for drinking water. In some places you’ll have large amounts of copper in the water because of copper piping. Depending on where your tap water comes from it could have lead, arsenic, dissolved solids, Maganesium, manganese, ect in it. There are drinking water standards for like 100+ elements and compounds that allow for a minuscule amount of these things to be in tap water and it still be safe to drink. With all the chemistry going on in a reef tank I personally wouldn’t touch anything but RODI or distilled water. I don’t have an RODI system so I used distilled for my reef and Betta and use additives to replenish the minerals the distillation process removes.

 

[count krunk]

Monitor CL/FB and here for a used system. I was able to pick up a 200gpd 6 stage for $150 that way.

I've since put $150 in upgrades into it but now it's one mean rodi machine!

 

[kerbfish]

I recently switched from tap water to RODI almost 2 months ago. For last 6 weeks my tank has been fallow with no fish. No matter how many water changes I have done...I can’t get nitrates down. Is it possible this is all still Lea hung out if my rocks from 2 years of tap water? Any one had this experience ?

 

[kerbfish]

Leaching out...

 

[Radicalrob1982]

I recently switched from tap water to RODI almost 2 months ago. For last 6 weeks my tank has been fallow with no fish. No matter how many water changes I have done...I can’t get nitrates down. Is it possible this is all still Lea hung out if my rocks from 2 years of tap water? Any one had this experience ?

I have no idea but it sounds possible. Tap water is pretty bad depending. It really should be gone though in that amount of time. How clean is your sand bed? It can be a nitrate tap. What are you using for filtration? It has to be coming from somewhere. Is your test kit ok?

 

[kerbfish]

I’ve used about 4 different test kits including Hanna Checker so it should be a true value.
At the moment I am just running 4 filter socks and big bag of activated carbon.

I will reintroduce my skimmer within the next few days. My sand bed shouldn’t be anymore of a trap than anyone else’s. Basically the way I see it is if you have sand under rocks then you have a lot of nitrates and phosphates trapped in the sand bed. That really should be much of an issue unless you stir it up.....

my tank had to be moved to change my floors, it was broken down and setup twice within a 2 week period. The LFS throughly rinsed my sand and of course back stuff was coming out as there are just certain a parts of the reef you can get to unless you destroy your coral reef everytime you vacuum.
I gravel vac during every single water change. Most guys don’t from what I hear .

I have vacuumed out my sump as well. I also tested the last batch of source RODI saltwater mix and as expected no nitrates.
Other than that I only have a porous large sediment sponge going into my sump return I have only rinsed that one out.

Again the number aren’t sky high but they should be coming down with no fish waste going in.....

 

[Clownfish_Boy]

I have no idea but it sounds possible. Tap water is pretty bad depending. It really should be gone though in that amount of time. How clean is your sand bed? It can be a nitrate tap. What are you using for filtration? It has to be coming from somewhere. Is your test kit ok?

Yes, the amount of detritus in the substrate could be the cause. I once had a FOWLR in which I had the same problem; nitrates through the roof; and it turned out that the UG filter (this was way back in the day) I had in it at the time was trapping so much detritus that it was producing a lot of nitrate from the decomposition. After removing the UG, reducing the amount of sand, and thoroughly cleaning the substrate the nitrates went down.