Do I need Di filter if...

[Ahetrick74]

Do I need Di filter if my RO water is measuring 5 TDS? Or is 5 good enough. Tank is 40 gal with a couple clowns, 2 small clown gobies, crabs, snails, anemone, and a couple soft corals.

 

[KStatefan]

I would not use 5 TDS water

 

[chipmunkofdoom2]

Yes. Many undesirable compounds are present in water purified by reverse osmosis that can only be removed by deionizing resins. These elements include, but are not limited to, copper, ammonium, silicates and phosphate.

Water quality is one of the most important components of a reef tank. I like saving a buck more than almost anyone else, but this is a bad place to do it.

 

[TriggerFinger]

Most of us would not but there are some who use unfiltered tap water.

 

[40g Nano]

It just depends on your city water. Some people use dechlorinated tap water, others use 1 tds RODI
I used 11 tds and I have had great growth in corals, but yesterday I got a resin and it is at 1

 

[Adamantium]

I would absolutely use one. 2-5 TDS is pretty much what we all end up with after RO, but then putting it through DI gets us to 0. You don't know what that 5 TDS contains, so you're better off using DI resin to polish it up. If it's copper, or silicates, you're gonna have an ugly/dead tank.

 

[Hellic]

I know this is an older thread, but it was one I found on a google search with DI questions, and whether or not I should add that stage. So I believe this post is still relevant.

One person said the DI resin removes phosphate and silicates, but that is actually not true. Phosphate and silicate can still be found with a simple test kit result after checking your rodi water. I even confirmed this through ICP testing. Where a DI resin does come in handy is by removing the last bit of TDS after the RO stage. How much TDS remains after your RO stage, you will have to determine with a TDS meter. After checking mine, my TDS was only at 003 ppm with a 2 year old membrane. I would actually say that a DI stage may be totally unnecessary for my water considering the results. It might actually prove more beneficial to use a phosphate/silicate removing filter, instead of a DI filter, to aid in algae control.

 

[Uncle99]

Start with 0. Stay with 0.
You dont know what the 5 is….

 

[naterealbig]

Yes. Many undesirable compounds are present in water purified by reverse osmosis that can only be removed by deionizing resins. These elements include, but are not limited to, copper, ammonium, silicates and phosphate.

Water quality is one of the most important components of a reef tank. I like saving a buck more than almost anyone else, but this is a bad place to do it.

This.

 

[naterealbig]

I would not use 5 TDS water

I wouldn't even use 0 TDS water without a DI filter.