How Vital is RO/DI water for a Reef Tank?

Shep

Reefing newb
Hey

I know that it really helps out a lot but is it something that you can make do with out? I am wondering because I do not really have the budget to handle a RO/DI unit. Is there a more affordable alternative that I could use in stead or do I need to save up and bite the bullet?

Thanks
-Tom
 
RO/DI water will have nothing else but water.

These are the benefits, and you decide if they are worth it.
1. You are starting with a known quantity when it comes to mixing your salt. This gives you better control of what you wish to add to the mix.
2. This also eliminates the possibility of the dissolved substances reacting with the salt mix and messing up your new saltwater.
3. No chlorine and other dissolved chemicals/metals. These substances can either be harmful to your tank inhabitants or feed nuisance algae, or perhaps both. *** You will need a chloramine prefilter if your water is treated with chloramine.
 
I think rodi water is one of the most vital parts of a reef tank. For starters, a lot of people who leave the hobby do so because of algae battles - and the number one source of algae problems is tap water. Second, I can say from personal experience that corals do not like bad water. This summer I waited too long to change my rodi filters and many of my corals suffered hugely because a lot of crap got through the bad filters and into the tank. Now I'm cleaning up the dead skeletons and praying a few others that haven't totally died off will make a recovery. I think in this hobby using rodi is a must. That said, if you have a small tank you can buy rodi water from your LFS (cheaper than buying it by the gallon from the grocery store). But depending on your tank size, saving up $100 for a rodi is worth it!
 
So how often do you have to replace the filters and the membrane? Also is it difficult to set up and maintain? Thanks everyone for helping me out :D.
 
So how often do you have to replace the filters and the membrane? Also is it difficult to set up and maintain? Thanks everyone for helping me out :D.

Having the following optional add-ons would make it easier to determine when to replace what.
1. Pressure gauge after the prefilters / before the RO membrane - A drop on water pressure at this stage compared to your usual supply pressure indicates that the prefilters are clogged and are inhibiting water flow.

2. Inline TDS meter after the RO membrane / before the DI cartridge - This tells you how much TDS made it past the prefilters and RO membrane. A rise in TDS readings at this stage could indicate that the RO membrane is degrading.

3. Inline TDS meter after the DI cartridge - this is your final product water. A rise in TDS readings here indicates that the DI resin is exhausted. In lieu of a TDS meter here, you could use color changing resin to give you a visual indication of how much of the DI resin has been exhausted.
 
OP ... I am probably a heart beat ahead of you on this. I have an ro/di system that an "expert" installed for me. Let me just say that bringing a bunch of things in, spreading them out across the floor, and then connecting them in with a rats nest of tubes is *not* an installation.

Moving forward, I discovered these guys. I have not bought anything from them as yet. But, I do intend to buy a dual TDS meter to help me know when to change filters. I am sure that this can be done by other ways, but i have a pretty full day and am all about a *little* bit of technology to help with my hobby.

RO/Di units are notorious for waste water. I think the number is like 10%. 10% of the water is filtered ro/di, the rest is waste. Sooooo, 50 gallons of ro/di equals 500 gallons of waste. They also have this which is high on the list. I am going to add the $78 option to my system.

As I said, I have not bought anything from them as yet, but their prices seem reasonable and they have many related necessary products.
 
That seems horrifically inefficient, it there a way to improve the ratio of good:waste? I followed the link and it does not say how much better their system is but even if it was twice as good it still would waste so much water.
 
Inefficient is an understatement and sets a value to ro/di water. As a result tho, I have reconsidered this 70%, or 50% and even a 30% monthly water change. I have a 90 reef tank, a 50g refugium, and a ~25g sump. The sump has a protein skimmer and that is it for filtering. I take out 0 to 9g a day at 3 gallons per siphon. This results in a 5% to 20% water change per week. I add salt directly to the center chamber of my sump proportional to the amount of water removed at that moment. The spec. grav. varies very little & the chemistry is spot on.

It does bother me that the salt does not sit and fully dissolve as many have indicated as a minimum into something like a 30g mixing barrel. But, I have been doing this for several months with zero issues.

I have quite a variety of plants in the refugium. So much so that the plants compete. I hate loosing a variety, but it does give perspective about the system chemistry. Certain varieties are definitely far more efficient at removing nitrates/nitrites than others and they flourish. Others die out completely and others "hover". I do not like losing a plant any more than a fish, but this stuff simply is just documented.

I also have a bazillion pods in the ref ... not to be too scientific in the count. But there is never any algae on the ref tank walls. There are a bazillion copepods tho and they do eat algae. There are also many amphipods which are funny and weird little critters. To all of that I added a mandarine goby (they only eat pods) which is considered "difficult". I rarely see the guy, but it is definitely not starving. Maybe a bit lonely tho.

Let sum up that I love my ro/di auto-top off water supply. I never give a thought to getting water. It is as good as you can get and is only a part of the insurance policy toward protecting the investment.
 
10:1 waste to product ratio is on the very low end of today's equipment.

The typical 75GPD units these days have a ratio closer to 4:1 at 55psi. With higher water supply pressure and an additional membrane conversion kit, you could further enhance the ratio.
Wastewater is a part of the RO/DI system though, so while it can be reduced it cannot be eliminated. So plan ahead and use the wastewater for something useful instead of sending it down the drain.

If your water supply pressure is lower than 55 psi, then you should invest in a booster pump as your RO/DI unit will not perform efficiently with deficient water pressure.
 
Good that you mentioned water supply pressure. Even with a booster pump my pressure is almost 40. Add another $150 to $200 ... it is not just a pump, but power supply & shutoff switches, etc.

I did not check mine before and did this reactively. But, I would still have put a ro/di system in anyway had I known before.
 
Good that you mentioned water supply pressure. Even with a booster pump my pressure is almost 40. Add another $150 to $200 ... it is not just a pump, but power supply & shutoff switches, etc.

I did not check mine before and did this reactively. But, I would still have put a ro/di system in anyway had I known before.

Is that 40psi coming out of the booster pump before it even hits any of the RO equipment?

40psi even with a booster pump is kinda low.
I would talk to RO/DI vendors and see if you have any other options of maximizing the efficiency of the RO membrane.
Maybe you can get a tighter flow restrictor at the wastewater line to compensate for the low incoming pressure - I do not know if that is even possible but just throwing some ideas your way.
 
I get that. I paid a so called aquarium expert to set up a greatly upgraded system. I have my own business, unrelated, so did not feel that I could put in the time on a "hobby". Of course after spending too much and the expert is absent too much, I started picking up where he left off. I am an engineer and he knew that. Any/every engineer will drill down into anything given the slightest motivation. In this case it was the investment upfront as the motivation, to be followed by protecting that investment ... the drilling.

I have not done very much drilling with ro/di. Well, just enough to understand what I don't understand. This is my next new frontier. I am still glad that I have my own ro/di system.
 
RO/DI is the most important part of your Reef. Water quality is every thing. Buying RO water from a store still has TDS in it. You want 0 Tds to eliminate algea blooms. For a couple of hundred bucks it's a gimme. Plus you don't have to carry jugs from your car.
 
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