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squid row
03/02/2017, 10:12 AM
We have RO filtration in our house. Is the addition of an RO/DI going to make a difference in water quality?

Tank right now is FOWLR only but I am setting up my first mixed reef tank in two months
BrotherNature
03/02/2017, 10:23 AM
RO/DI water is definitely much purer than RO water, but it's not like RO water can't work. If you haven't already you might want to check the TDS of your RO water. This will kind of give you an idea of what your working with.
nereefpat
03/02/2017, 10:25 AM
It depends. Do you measure the TDS on the RO water?

In general, RO removes about 95% of the TDS, and DI gets TDS to zero.
mcgyvr
03/02/2017, 11:30 AM
And that extra 5% could be nothing to worry about or it could be (unlikely but possible)..
Chemical analysis would be the only way to determine what that extra % is..

So the answer is "yes" it can make a difference in water quality..
But "no" we can't tell you if adding DI will really be beneficial or not..
Elricsfate
03/02/2017, 11:35 AM
I have pondered this question as well.

I have well water. The water from my tap reads 14 TDS untreated. After the RO stage it is 2-3. After DI it is 0.

Since DI resin is expensive, and apparently high CO2 in my water is causing me to burn through resin quickly, I am considering not using it.
surfingdude
03/02/2017, 03:05 PM
I have pondered this question as well.

I have well water. The water from my tap reads 14 TDS untreated. After the RO stage it is 2-3. After DI it is 0.

Since DI resin is expensive, and apparently high CO2 in my water is causing me to burn through resin quickly, I am considering not using it.

I have well also and thats what I was thinking when i started...I just use ro..my tds is around 5, give or take. still worries me and havent gone the resin route yet. Been up and running for about 3 months. Most people said I would be fine, but its still not 100% perfect.
brianbrainstein
03/02/2017, 09:51 PM
I had about 20 TDS with just an RO filter. Did a 30 gallon water change on my 250 gallon system and immediately got an algae bloom. Next 30 gallon water change, immediate algae bloom. Bought the DI resin-no algae bloom after the last 3 water changes. You may just need to experiment with it, but for the price of a fish/coral, the resin is worth it to me now.


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