To RODI or not to RODI...

[VladSI]

I've got whole house water filtration that gives 47 TDS at my sink and 30 TDS through an inline carbon block .5 micron filter going to the fridge. I'll be aging the salt mix for at least a few days which will allow the 2ppm chlorine coming from the tap to vent/burn off. Water from carbon filter is 0ppm chlorine already.

Is it really worth the expense and hassle for RODI with numbers that low? Need some opinions from senior reefers.

-Vlad

 

[theMeat]

Little confused. Where are you getting the water from. Sink, fridge, ?
What is the total tds, not just chlorine, from where you're getting it? Where have you been getting water up till now? Fish only, reef tank?

 

[Kworker]

Get an RODI unit.

 

[noelskii]

Are you doing a FOWLR tank? There's really no room for cutting corners in a reef tank...

 

[cmantis]

Aging the water to remove chlorine is a FW thing. Anything over 3 TDS for a reef is not good and is when those of us with RODI usually (or should) change the filters. For a fish only tank a RODI is not absolutely necessary but if you think you may ever want corals and don't use RODI those rocks will absorb nitrates and will be difficult to scrub of it. So the answer is yes use RODI water it is worth the investment in my opinion.

 

[ReefBum]

RODI all the way if you are keeping corals. Algae outbreaks can be problematic on many fronts.

 

[VladSI]

This will be a mixed reef. I'm currently using the 30ppm TDS water for a 6g coral-only nano without any issues but want to do this the right way when I get my 68g up and running. I've read elsewhere that in high TDS tap water areas elsewhere in the country (200-300) - people are getting 20-30ppm TDS out of their RODIs and are using that successfully in their tanks. My thoughts were if they are successful with 20-30 from their RODI, why should I go through the hassle and expense to get my 30ppm down to zero?

So far the feedback on this thread is to not cut any corners which makes sense to me. I'll follow that advice. I'll look into adding just the membrane portion to my already established filtration system.

Thanks everyone!

-Vlad

 

[theMeat]

DI resin is important too, it will remove silica, which will/could build up and become a problem. If in an area where tds is 200-300, their levels after ro/di should not be 20-30 tds unless something is not right. Can you make a reef tank work with those numbers, sure, but for a reef tank it is certainly cheaper on your time, effort, and money to get an rodi unit going.

 

[VladSI]

DI resin is important too, it will remove silica, which will/could build up and become a problem. If in an area where tds is 200-300, their levels after ro/di should not be 20-30 tds unless something is not right. Can you make a reef tank work with those numbers, sure, but for a reef tank it is certainly cheaper on your time, effort, and money to get an rodi unit going.

Thanks for that info - I was under the impression that the membrane does both.

 

[Spracklcat]

Silica being a problem is a bit of an old myth. Some people dose silica nowadays to help with nutrient export and to help keep sponges. That said, RODI is definitely a good idea for all the other benefits in a full reef.

 

[Alfredo De La Fe]

I used to be in the camp that a basic RO unit was all that was needed (I live in Manhattan). Gotta tell you, the difference when you are using RO/DI is HUGE. I am talking about how much algae I end up getting. Before RO/DI I had to use my glass cleaner magnet every couple of days. Now with RO/DI I have not had to use it in TWO WEEKS!

Definitely worth the investment. I got my six stage RO/DI with a 3.5 gallon storage tank and a separate hose (with valve) for "reef tank" which takes the RO water from the tank and passes it through the DI cartridge for $130 on ebay with free shipping. Best investment I ever made for my tank AND my home (we now cook and drink RO water and RO/DI for my tank!)

Alfred

 

[theMeat]

Silica being a problem is a bit of an old myth. Some people dose silica nowadays to help with nutrient export and to help keep sponges. That said, RODI is definitely a good idea for all the other benefits in a full reef.

There have been some interesting experimenting done, with sometimes surprising results. Except there's alot of variables that are impossible to calculate therefor plan for. Like the amount and sources of silicates. Then there's soluble vs un-soluble, as well as how many sources consume, and how much does each consume, how fast do they grow, being able to consume more. How much leaches in and how much dissipates on it's own, etc.
Can only say that have only seen systems improve when ro/di has been used, at least around these parts. Even noticeable when a poorly running rodi is fixed.