In the past, I have had every type of freshwater tank that anyone can have. I have used tap water with Prime and always had a battle with algae. When I start a saltwater tank;yes, I was using Prime with tap water and the battle with algae start. I did some research, I took a chemistry class in high school and college. After doing the research on reef tanks and RODI water. I figure out what I was doing wrong. It is ALWAYS best to use RODI, but if you are short on money it is ok to use RO water. But I REALLY recommend to use RODI water because you have 0 TDS. With 0 TSD, you have less problems. I have been using RODI water for about 10 months now and my reef tank is actually doing better than Tap with Prime. I still keep a bottle of Prime just in cause a shipment for the filters for my RODI system does not coming on time. But I always try my best to have filters coming in before I run out of them. I also have TWO membranes so I have less waste water. I am working on buying a booster so then I will even have almost no waste water. RODI with Two membranes and a booster is the BEST way to go for Aquariums. If you are not then you will be spending more money on Prime and other chemicals. I different know after 15 years of experience with aquatic life.
Tap water and Prime for initial fill
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redfishbluefish
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Oh boy! Giving you the heads up Dave.....someone by the name of @AZDesertRat has a different opinion about what you said here:
Hopefully he'll give you his two cents on dual membranes.
Hopefully he'll give you his two cents on dual membranes.
There are Ro/do systems for sale that have dual membranes. I did it because my TDS where I live in NJ is anywhere from 350 to 500. I tried one membrane which only got my tds down to 50. Then the DI resin was be eaten up every time I made 50 gallons. Since I put the Dual membrane, the Di resin is lasting much more. The tds after the dual membranes is now 13- 10 tds. I am using two 50 gpd membranes. I got the idea from this website .
saltyphish
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Not to mention what else is in the water! It's the unknowns that makes that a risky choice. Ro/DI all the way!
Prime does not stop the phos that is found in the tap water. By using Prime or products like it does not destroy ALL the harmful things that are in tap water. I have used Tap water and Ro/Di water. I can tell a major difference like low to no Phos. Corals are better looking and doing better than using Tap. I have spend more money and time when using Tap. All, I can say is have fun making this companies richer by buy ALL those chemicals to make it look pretty like mine. While all I do is dosing Cal, Alk, MG and trace minerals. Making salt water without those crazy chemicals ot make the water safe for the aquariums.
Never said prime does any of that. BTW I don't use prime or add cal, mag, Alk or trace elements. Between what you dose and spend on RODI you are contributing more money to companies then I am.
If you are that worried about phosphates get GFO much cheaper and eaisier then making RODI water.
I find it funny that this is even a discussion, especially since the OP already owns a RO/DI unit. What possible con could there be to filling up with RO/DI? Just lazy because it takes too long and may cost an extra $10 on your water bill? lol
Randy Holmes-Farley
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Do you have a reef tank?
moulton1853
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I am new at this and everyone swears by rodi water. I used tap, I know my bad, but no problems so far. I waited till the tank is fully cycled to put anything in it. Had a small diatom bloom and then added a clean up crew. Put in a coral and a fish and they are both doing well. No bad algea and a nice patch of lime green coralline is starting to grow. Phosphates and nitrates are both low. The only issue is the alk and calcium are a little high but that should come down on its own.
Akida17th
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I'd purchase a much better RODI system. A 4 to 1 rejection rate is quite high. Hydrologic manufactures some of the best RO units in the country. Their Triton (what I utilize) is a 2 to 1 rate and their DI last much longer then most I've used. They also have a beast of an RO unit that produces 900gpd, the Evolution! The Triton works perfect for reef applications though.
Akida17th
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I hope you're not referring to the rejection water. That should NEVER be given to plants or any living creature. It's concentrated crap and would harm plants and life.
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Depends on your water, of course. My RO/DI waste water is much better than many folks incoming tap water, and if you have a use for it, it would be foolish to waste it out of unwarranted fears about its being contaminated.
For folks with the usual 4:1 ratio of waste to effluent, the waste water only comes out with a 20% higher load of what's in it from the tap, which in the case of my tap water (less than 100 ppm TDS) is far better than what folks get as incoming tap water in much of the country.
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So you have a reef tank and you never add any alkalinity?
If that is so, it must not have much in the way of thriving coralline or hard corals, since topping off with tap water could never keep up in most typical mixed reefs.
Akida17th
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You know I didn't add in the ratio in comparison to the concentration. You have a solid point there. However most higher end RODI filters should have a 2 to 1 ratio which means the rejection water is so highly concentrated (usually 50% or more then your incoming tap) that it's actually labeled as harmful through TDS guidelines. The average tap water in American contains around 250-300 ppm's which means on average your rejection water would be 500ppm and higher which is toxic.
Vendors should clarify the conditions under which you can safely and economically reduce the recommended waste ratio from 4:1 to anything less. The number one determining factor is tap water hardness. If you are not using softened water don't even think about reducing the waste ratio as it will prematurely plug or foul the membrane due to lack of velocity needed to flush the solids off of and away from the membrane fabric. If you have softened water but still have higher than normal TDS you can probably get away with a 3:1 waste ratio and still realize good membrane life. If you have both softened water and much lower than normal TDS then you can possibly ge taway with a 2:1 ratio but no vendor can blindly sell a system to you and guarantee results without knowing your specific conditions. The ONLY system I have personally seen or used that can do so is the Spectrapure MaxCap UHE due to the fact it uses stored DI water to both flush and pickle or store the membrane in DI wate rwhen the system is inactive. This is very different than any other system around since most use tap water to flush and then only via a flush kit which is more a feel good item than actually doing anything useful since it only flushes the waste side and not the treated side were TDS creep resides.
Before buying any RO/DI system you need to have a good idea of your tap water quality so the vendor can tailor the system to your needs. No two users have the exact same conditions and RO/DI systems are not or should not be plug and play if you expect it to function well and last as long as it should.
500 TDS is not toxic, at least if the TDS in the water to begin with was up to potable water standards. There is no MCL or maximum contaminant level for TDS, it is considered an asthetic problem and not a health risk. The 500 is a guideline only and not anything enforcable. Many communities here in AZ are well over 500 all the time, mine is in the 600-650 range most of the time and parts of the Phoenix metro area are over 1600 from the tap and taste quite good.
Before buying any RO/DI system you need to have a good idea of your tap water quality so the vendor can tailor the system to your needs. No two users have the exact same conditions and RO/DI systems are not or should not be plug and play if you expect it to function well and last as long as it should.
500 TDS is not toxic, at least if the TDS in the water to begin with was up to potable water standards. There is no MCL or maximum contaminant level for TDS, it is considered an asthetic problem and not a health risk. The 500 is a guideline only and not anything enforcable. Many communities here in AZ are well over 500 all the time, mine is in the 600-650 range most of the time and parts of the Phoenix metro area are over 1600 from the tap and taste quite good.
Akida17th
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EPA max containment level for drinking water is 500 ppm. 1600 ppm water you couldn't pay me to drink that, sorry. I hear what you're saying but their are regulations for a reason. The only water I've ever seen personally over 500 was well water since the surrounding pollution creeps into the ground contaminating the water, and I live in Philadelphia which tells you something lol. Also, any and all Reverse Osmosis manufacturers will advise against using the rejection water.
