RO/DI Top off water

[Phyl]

The more I know the less I realize I really do know...

When you add RO/DI water to your tank for topoffs what do you do to prepare it?

[skennelly]

Nothing....just make sure its similar temperature to the tank water.

[Serge]

Since I don't if you have a RODI unit, I will be brief:

RODI unit is connected to your main water supply pipe. Two tubes come out of it. The one that interests us, is for filtered water which you collect in a clean container (READ: Fishies only) and then just pour into your tank as needed. Of course, if the water is too cold, you will have to warm it up a bit. HTH.

8)

[Phyl]

*RIGHT* But temperature isn't the only thing severely out of wack with the RO/DI water! Water out of the RO/DI comes with a PH of say... SEVEN! When my tank is up around 8.2! Should we be buffering the water for topoff up to the 8.2? What about airating it if it has been sitting? Seems to me that there might be more involved in this whole top off thing than meets the eye? Lets say I top off once a week and usually put in around 1.5-2g when I top off (into my 120 tank). I've been pouring it out of the jug and into the tank. Suddenly I'm thinking that's not so smart. I'm wondering what the skilled fishkeepers are doing in this regard!

[tripper]

All I do with topoffs is add some dechlorinator and let the water sit for 24 hours. I do not match temperature because I am only adding about 1-2 gallons every 2 days to a 72G tank. As far as PH goes, technically, the water that is evaporating will have the same PH as the RO/DI water. This means that the tank water's PH is rising slightly as the water evaporates and therefor the fresh RO/DI water would pull the PH back down to the apporpriate level. HTH

tripper

[echoplex]

Correct me if I'm wrong but I believe not only does the Reverse Osmosis process remove Chlorine and Chloramine, but it also aerates the water really well. PH and Temperature are the only things I adjust, and even then only if the tank is already stressed for some reason. Otherwise I just dump raw RO/DI right in the sump.

CTA RO membranes remove chlorine/chloramine on their own.
TFC RO membranes must have chlorine/chloramine removed by prefiltering/carbon.

[Phyl]

I always have 6 jugs full of RO/DI at the ready so it probably isn't so aerated by the time I get to use it. I had read some stuff about people buffering their water prior to adding it, but that looks like it isn't the norm (here at least).

[BillyZ]

I don't do anything to top off water other than brig it to room temp. All thats evaporated is pure water, that's all you should be putting in to replace it, IMO.

[Nim Chimpsky]

Without a RO/DI unit, is this the same water I can buy from the grocery store as distilled? Can I buy that and pour it straight in to top off after evaporation?

[ellisz]

I put mine in a 44 gal container. Then transfer some to 3 5 gal water jugs. I have a top off conatiner that I put 5 or 10 gal of water in. When the float calls for water, it pumps a little in. I don't do anything to the water... it is room temp and don't know what the PH is. I only add a little at a time since the float is calling for water when it needs it. I used to mix my kalk in the top off water.

No dechlor needed in RO/DI water.

[melosu58]

I`ve been pouring a gallon a day of ro water straight in the top of the tank for eight years with no problems. Its a little late for ya`ll to tell me there`s a problem with that.

[adacaro]

I sure have a hard time buffing my DI water the PH is so low I alñmost put the whole jar inside the water I had for a water change. This caused my calcium to go downto 260 now I have two problems. Does anyone know of a buffer that works quick. I need it bad.

[melosu58]

A water change works for me. Try a 20% PWC

[seaham358]

I add nothing to the top off water, add water to my auto top off system and the tank gets water when it needs it.. IMO once you start adding chemicals to the water we create other problems somewhere down the road..
I learned this the hard way with my FW tank, I ended up killing a couple nice bamboo shrimp messing with that **** Ph buffer crap..