Why RO/DI ???

Cassian · Nov 27, 2019

Hello all,
I’ve been doing research on RO/DI for reef tanks. I have an RO system that I have used for my tank, but I’m considering upgrading to a larger units during the Black Friday sales. But first, here’s my question: Do I need an RO unit if I am on good quality well water? I am in Missouri, so the well water is naturally high in cal and mag, which is great for my corals. But it also has a TDS if 330. Here’s the funny thing. My corals do better on the well water than they do with my RO system. Why is this? Should I stick with well water or should I invest in another RO system for my tank?

45ZoaGarden · Nov 27, 2019

LukeWolf said:
Hello all,
I’ve been doing research on RO/DI for reef tanks. I have an RO system that I have used for my tank, but I’m considering upgrading to a larger units during the Black Friday sales. But first, here’s my question: Do I need an RO unit if I am on good quality well water? I am in Missouri, so the well water is naturally high in cal and mag, which is great for my corals. But it also has a TDS if 330. Here’s the funny thing. My corals do better on the well water than they do with my RO system. Why is this? Should I stick with well water or should I invest in another RO system for my tank?

Get an ro/di system. Your well water is bound to have some heavy metals or Atleast some form of S or Cl. Ro/Di water is STERILE. This means there’s nothing in it. It is pure H2O. It’s so sterile in fact, you can get sick from drinking it because if it’s lack of nutrients. Now, why use sterile water? Because your salt mix already has nutrients. For ato’s you are only replacing lost H20. The nutrients don’t leave your tank with evaporation. When using tap water or well water, you’re adding excess nutrients because you’re almost double dipping. You get nutrients in water AND in the salt mix if you do that. When you double down on nutrients, you’ll start to have algae problems. I’d rather know exactly what is going into the system then not knowing. With well water, it’s a mystery. With ro/di water, you know exactly what’s going in, water and water only.

pdxmonkeyboy · Nov 27, 2019

Also, be aware that if your ph is really high in your well water you may have to out gas it with a bubbler before pumping it through your di unit or it will exhaust your DI resin quickly

Hemmdog · Nov 27, 2019

45ZoaGarden said:
Get an ro/di system. Your well water is bound to have some heavy metals or Atleast some form of S or Cl. Ro/Di water is STERILE. This means there’s nothing in it. It is pure H2O. It’s so sterile in fact, you can get sick from drinking it because if it’s lack of nutrients. Now, why use sterile water? Because your salt mix already has nutrients. For ato’s you are only replacing lost H20. The nutrients don’t leave your tank with evaporation. When using tap water or well water, you’re adding excess nutrients because you’re almost double dipping. You get nutrients in water AND in the salt mix if you do that. When you double down on nutrients, you’ll start to have algae problems. I’d rather know exactly what is going into the system then not knowing. With well water, it’s a mystery. With ro/di water, you know exactly what’s going in, water and water only.

+1 , perfect answer