Initial fill up: Tap or RO water?

LIreefguy106 · Apr 5, 2016

Hello fellow reefers,

I'm starting up a 90g but don't have a RODI system (and being that I can't swing the additional costs right now, don't have any plans of getting one anytime soon). So the question is can I run tap water to fill up the tank and then let it cycle through my sterilizer and gfo reactor? Or do I need to go back and forth to my lfs and get RO. Any thoughts or personal experience in this conundrum?

Thanks for the advice in advance.

Downbeach · Apr 5, 2016

I used tap water to check my system for leaks, but drained it, and replaced it with RO/DI water. I would invest in an RO/DI unit before a sterilizer or any reactor's. Tap water can/will contain many unwanted heavy metals, i.e. copper, lead, etc. that would be detrimental to your system, and an RO/DI unit is the only thing that will remove them.

MOPAR · Apr 5, 2016

I definitely wouldn't recommend it. If a rodi unit is out of the question then go the LFS route. It will be a pain but well worth it. Starting out on the right foot is key it will save you money and headaches later on.

Lionfish Lair · Apr 5, 2016

I've done it both ways I've never noticed a difference in the outcome. The last tank I cycled with RO/DI ended up having an uglier algae than the one that was cycling at the same time with tap. It doesn't mean automatic algae issues. Look at all the people that use RO/DI that still have nuisance algae issues... tonnes. If you don't do proper tank maintenance, you're going to have issues no matter what your source.

After my tank cycles, I do a large water change with RO/DI.

ermartin · Apr 5, 2016

LIreefguy106 said:
Hello fellow reefers,

I'm starting up a 90g but don't have a RODI system (and being that I can't swing the additional costs right now, don't have any plans of getting one anytime soon). So the question is can I run tap water to fill up the tank and then let it cycle through my sterilizer and gfo reactor? Or do I need to go back and forth to my lfs and get RO. Any thoughts or personal experience in this conundrum?

Thanks for the advice in advance.

I have always used tap but a lot depends on the source of your TAP. As my system cycles I change out using RODI and I run a sterilizer only during the cycle. I also start with dead rock

AZDesertRat · Apr 5, 2016

Its not worth the risk, RO/DI or distilled water from the very start. "If its worth doing, its worth doing right the first time." Since you have no control over your tap water quality I would not recommend using it, and I am a water treatment plant operator and supervisor by profession. I wouldn't hesitate to drink it but drinking water quality and reef quality are two different things.

I always recommend buying a RO/DI or having a trusted source of RO/DI before even buying anything else or setting a reef up. Water is the single largest ingredient in a reef system and everything depends on its quality and its stability. When you have a RO/DI you alone control its quality and you don't depend on anyone else. $125 is cheap insurance when you consider a single coral or fish can cost you that alone, it sucks to lose a whole system over water quality.

JackDE · Apr 5, 2016

I started with Tap. I am only 3 months in. I have fish now and my dry rock has become live but I have seen very little bad algae. Maybe 2 rocks with some on it.

Lionfish Lair · Apr 5, 2016

If you cycle with tap, convert over to RO/DI. You don't want to be continuously pouring conditioner in your water.

smh254 · Apr 5, 2016

I used tap water to start 2 tanks. Then used RO/DI after the cycle. My tap waters TDS is only 85

Lionfish Lair · Apr 5, 2016

My TDS is 400-500+. I live in Los Angeles. I've cycled over a 100 tanks.

TheEngineer · Apr 5, 2016

If you can get RODI, I'd say get RODI. If it is too much of a pain to do the initial fill, don't worry about it, just use tap. You're going to have so much funk and junk coming off of everything during your cycle that what comes in from your tap water is probably pretty minimal.

Salt It Away · Apr 5, 2016

LIreefguy106 said:
Hello fellow reefers,

I'm starting up a 90g but don't have a RODI system (and being that I can't swing the additional costs right now, don't have any plans of getting one anytime soon). So the question is can I run tap water to fill up the tank and then let it cycle through my sterilizer and gfo reactor? Or do I need to go back and forth to my lfs and get RO. Any thoughts or personal experience in this conundrum?

Thanks for the advice in advance.

See if your lfs offers delivery service. I have 3 Brute containers that I keep (2 fresh and 1 salt). He backs up his truck, runs a hose to my storage area and drops 70-80 gals of rodi. Yes, more $ than making it but more convenient than a slew of back and forth trips)

PatW · Apr 5, 2016

Using tap will cost you nothing except the salt. But you take a risk with heavy metals, copper, even organic compounds. If you buy RODI, you are talking about $50 just filling the tank. You can get a spectra pure refurbished unit for that much.

My tank had a series of algal blooms caused by nutrient leaching from my dry rock. I am glad I used RODI because otherwise I would have wondered what the source of the problem was. Now I know. I think if I had it to do over, I would have cured the rock for a month or longer.

jkopfishman · Apr 5, 2016

I started a tank with tap water and had nothing but problems. Especially hair algae. Corals didn't do well. Seemed nothing did well. I wanted to quit until a buddy told me to use ro/di water. Wow what a difference. Now years into the hobby I have 3 reef tanks and a frag tank that r great. I'd never use anything but ro/di. U can get a 50 gal a day ro buddy for under $75 at some places. Get a used one for less than that. So the $50 ur gonna spend at the LFS for ro water could b used for the ro buddy instead and u will b way happier. Believe me iv done it.

Reeferfourlife · Apr 5, 2016

If money is tight, you can ask you local reefers for there water when they do water change. But you will need about 30 to 40 percent new rodi water during fill up. Its like having an older reef tank and doing a big water change. Find out about the salt water you getting first tho. Make sure they dont have issues with their tank and had to do the water to correct something major.

PedroDrummer · Apr 5, 2016

Definitely R.O. I never mess with tap.

shoelaceike · Apr 5, 2016

It all depends on how the tap water is where ur from.... Chances are it's fine....my initial fill was with tap, only because it was too much to run that much trough an RO.

jetmaker · Apr 5, 2016

LIreefguy106 said:
Hello fellow reefers,

I'm starting up a 90g but don't have a RODI system (and being that I can't swing the additional costs right now, don't have any plans of getting one anytime soon). So the question is can I run tap water to fill up the tank and then let it cycle through my sterilizer and gfo reactor? Or do I need to go back and forth to my lfs and get RO. Any thoughts or personal experience in this conundrum?

Thanks for the advice in advance.

I filled mine up with tap water came out fine just use some prime and run carbon and you will be fine. How ever all top off is with Rodi I have a unit.

AZDesertRat · Apr 5, 2016

Chances are it isn't fine. Tap water is treated to drinking water standards not reef standards. The human gut is amazing and tolerant of many things, your corals are not.
If you start with unknown quality water you will never ever be able to remove all the effects, it is mathematically impossible no matter how many or how large the water changes are. Metals will soak into your rock and substrate, silicates will get in and much more.
Again, a reef is a big commitment and you need to be in it for the long haul so do it right or don't do it at all. If you are that impatient at this point I really hate to see what your future looks like. I don't want to discourage you but that is the way it is in this hobby. Corals can live for decades, I have some that are well over 30 years old I my systems. Fish can live 15-20 years, be a responsible reefkeeper and provide the best environment you can and enjoy all the years you can get out of it. Remember water is the single largest ingredient and you can produce 0 TDS RO/DI water for an average 5 cents a gallon I including water and sewer charges as well as replacement filters and resin. dang cheap insurance and you control it
It's absolutely foolish and wreckless to not own a RO/DI if you have anything over a 10 gallon system and take the hobby seriously. I can make hundreds of gallons of water for what one single dead coral or fish costs due to being cheap or wreckless.
35 years ago I started with tap water but it didn't take long to switch to purchased RO only drinking water then buying my first RO and soon converting that to RO/DI. The tank conditions improved each time and I have never looked back nor doubtedit was the best thing I could have done for the health of my systems.

Prime removes nothing except chlorine. Everything else is bound up so it is not as toxicbut it hasn't gone anywhere, don't let anyone tell you any different.