Reverse Osmosis Advice

[Fmjets11]

My house I purchased came with an RO drinking water faucet and was fully functional hooked up. I recently unhooked it and just ran the line to the basement to use as water for my saltwater tank but have a few questions.

1. Is there any harm in filling up a 35 gallon (brand new) trashcan with water and letting it sit for weeks without using it? I just always want to have my water source ready to go because it only puts out 3-4 gallons per 8 hours but I am only doing water changes 12 gallons per week or so.

2. How can you tell if the filters need replaced? My guess is that they havent been replaced in a couple of years but it also has not been used in a long time.

3. How much better is RO water over regular tap water?

4. Is there anything else I need to know about this before using it?

Thanks for your help!

 

[Sniperhank]

I make my water up about a week in advance. I wouldn't have it sit around much longer than that.
In terms on how often the filters need replaced, that can vary on how poor or good your water is. I change my filters every couple of months, but I have a 5 stage RO/DI unit that I use ontop of the normal filtration for my house.
RO water is better than tap water because it is removing the larger particles from the water, the total disolved solids (TDS). In terms of a FOWLR system, this water would do the job since your fish will not need the pristine water quality that some of the reef setups desire, and then incorporate DI to 0 our the TDS readings.
Hope this helps.

 

[Dmann]

Some people get away with using tap water with little to no problems others its a nightmare. It's not bad for the fish but can be a headache for algae and unwanted bacteria and want not. I only use ro/di water at 0 TDS.

Best way to tell if the filters need to be changed is a TDS METER on your output.

 

[kay-bee19]

How much better is RO water over regular tap water?

A decent RO membrane will remove perhaps 95-97% of the total dissolved solids (TDS) from tap water. An excellent RO membrane will remove 98-99%+.

How can you tell if the filters need replaced?My guess is that they havent been replaced in a couple of years but it also has not been used in a long time.

You'll require a TDS meter to determine that as Dmann has stated, and perhaps know the starting total dissolved solids (TDS) rate of the membrane.

The TDS meter will let you know the TDS of the tap water and RO water with those you can determine the TDS rejection rate. Knowing the starting TDS rejection rate will give you an idea of how far this rate has decreased over time.

Without knowing the starting rejection rate and if the water is being used for a non-reef system you could set your own TDS maximum limits. For example changing the membrane out when RO TDS increases to 20ppm or if the rejection rate drops to 90% or less. I'm assuming the system is not a RO/DI unit (higher RO water TDS will accelerate DI resin expenditure).

 

[TheTodd]

I got a TDS meter on eBay a few weeks ago. It was something like $15 shipped. RO water from a Glacier Water unit outside a local grocery store was like .003 and my tap was a lot higher. I wrote it down at home and will try to post later. I also tested random things like water filtered through my refrigerator (barely made a difference), a couple bottled drinking waters, etc. It was amazing how big of a difference there was.

 

[Dmann]

So ro water is safe to drink? But I heard ro/di is not good for you to drink? Is this right? And why?

 

[Sniperhank]

So ro water is safe to drink? But I heard ro/di is not good for you to drink? Is this right? And why?

It takes all solids out of the water. I wouldn't drink it for that reason personally. Only thing I can think of in terms of not being safe isn't from drinking, but from someone using ro water in a nettle pot and ended up putting a brain eating parasite in their head that way. Was in Florida a year or 2 ago if i remember when I heard the story on the news correctly.

 

[Keithhjs]

Drinking RO water is perfectly fine. Myself I would skip drinking RO/DI. The DI (deionized) has left the water molecules lacking ions and therefore "aggressive", taking ions from what it comes in contact with. If you install a RO/DI unit with an added drinking faucet it instructs to split off the drinking water before the DI resin chamber(s). Also, I leave my RO/DI in a 28 gallon brute trash can with a secondary 5 gallon bucket (on my ATO system) both with floats for automatic make/up water, and they are always left full. Never empty unless I decide to drain and clean it.

 

[huma-huma]

Brs( bulk reef supply) sells TSS meters that can be installed on most ro/ rodi units. Make sure you spend the extra money and get the 2/3 lead testers . It'll test the Tds in more than one spot