[MaineAquatics]

I don't like my tap water... I just don't.. so what is so bad about using RODI water in a planted tank if I'm going to dose macro and micros EI? Won't the dosing replace most of what was lost? Also I'm only going to be stocking the fish very lightly so I don't see how it could effect them enough not to use it...

A touch of sodium bicarbonate could take care of the low ph/kh issues as well...

 

[KrazyFish]

many people do use RODI in their tanks and then simply adjust the water back to the target parameters by using various additives ie. baking soda, GH boosters, calcium etc. The thing is unless you have extremely poor water there is really no need to do this usually. Ther are some but most plants in the hobby will adjust to the water. You just end up spending more time and money if you go with RODI.

If you still decide to use RODI you could try blending it with your tap water to find a happy point (save money). And if you go %100 RO especially make sure that your plants have enough magnesium and calcium in the WC too - you would need a GH booster 4 sure (either way), but maybe also some epsom salts and Calcium nitrate to supplement your dosing (particullarly at %100 RO.

 

[wkndracer]

My tap is crap so I couldn't keep my tank filled without RO water.
Along with sodium bicarbonate (Baking Soda for some reading this) that does a great job for me here the GH component needs to be addressed not just macro and micros. Mostly Calcium (Ca) and Magnesium (Mg) it does contain other minerals that are needed. I use the GLA Ultimate Booster from Orlando because I find it mixes and stores very well for me.
The components he uses are reported to be identical to Equilibrium only a much finer grind on the minerals used. I can attest to it mixing and storing much better for a fact!

I don't use a final DI post membrane and haven't in 2yrs. Product water measures 2ppmTDS, 0.0dGH, 0.0dKH. Removing silicate and mineral content from my well water ended my major tanking issues. For freshwater aquarium use I believe DI is only required if you have a known copper present in you're source water.

 

[rbarn]

I don't like my tap water... I just don't.. so what is so bad about using RODI water in a planted tank if I'm going to dose macro and micros EI? Won't the dosing replace most of what was lost? Also I'm only going to be stocking the fish very lightly so I don't see how it could effect them enough not to use it...

A touch of sodium bicarbonate could take care of the low ph/kh issues as well...

Problem you are always chasing yourself in a circle trying to get the water just right. Consistency is more critical than any particular hardness reading for the most part.

 

[wkndracer]

Problem you are always chasing yourself in a circle trying to get the water just right. Consistency is more critical than any particular hardness reading for the most part.

With that 'most part' being no problems other than a general hardness reading absolutely true.
Consistency is important true enough also in all things done maintaining an aquarium but does this apply simply because it's RO being talked about? I have used nothing but RO here due to what was tested in my well. Using a salt regen whole house RO system for all tap use made neither the well or the house water anything I could use and tank plants.

Chasing your tail like a puppy is a people thing.

I'm posting this regarding the concerns about osmotic pressure swings, pH shifts basically all the posted yada yada that abound on the internet. Most are saltwater related or made by those without using an RO system to begin with and are more hype then genuine points of concern when it comes to freshwater tanking. I've been doing this long enough to have run the gambit. Dirtied my reservoir with minerals mixing before adding, believing stored RO could become stale or toxic you name it and I've probably been worried about it. Truth is none of it is a big deal and most is flat out BS. The reality as I see it is in my posted threads right here on this site. 22 glass boxes are posted on this site under my user name full of weeds and now currently 3 generations of in house spawned and raised fish. Tanks are full.

2ppmTDS, 0.0dGH, 0.0dKH, temperature matched and aerated RO is pumped directly into my tanks in water changes as large as 90% without a single loss of fish or plant makes me just shake my head reading most of what I see in print on the web. Once the water is in the tank the minerals are added by pouring them in no drama required, the added work is minimal. The expense annually for the minerals even with my current tank volumes is <$100.00.

Baking soda and GH booster allow me to precisely set my water parameters and while osmotic pressure does shift for an hour or so during the change for the creatures I house that has meant nothing to them, still here, still swimming, still breeding.
:fish:

 

[LobsterOfJustice]

I'm setting up my first planted tank... I have an RODI I used on my saltwater reef setup - can I run water through the prefilters of the RODI (sediment and carbon blocks) and use this in my tank? This should remove chemicals from the water (like chlorine) but not dissolved solids (minerals), right?