A question about RO/DI

[Tommo]

Now i am almost ready "give or take a week or 2" to fill my 5x2x2 planted.

Now my question is whats the best mix for the tank?
Ro water only ?
or
Ro/Di water ?
or Ro/Tap water "my tds is about 20ppm"
or
Di/Tap water "Tds 20ppm"

[rex82]

what does your straight tap measure? PH, KH, GH,

[Vspec]

RO generally gets you about 95% there with pristine water, the DI is the final stage (an add on if you will) that gets you over the top. So my response is RO/DI

[Tommo]

But , Don't you think that some minerals would need to be in the water ? "when i had my reeftank i used only DI" as you dont want any minerals what so ever.

[rex82]

pure water is not good for much.....wont support life or PH for that matter

[ILLUSN]

Mate your in melbourne, tap water is fine, if you want to get fancy do a 50 50 mix of tap water and either ro or DI but you wont need it.

[Vspec]

Freshwater applications yeah no worries, use the tap water if you wish, RO/DI is used for salt water for a reason. Everyone preaches acidic water is challenging, & yeah i'll agree, however dont kid yourself. Saltwater would still be considered one of the fastest changing enviroments in the world. We're not all space monkeys playing with ourselves, there's a reason for deploying it. If you dont, your discover that reason sooner rather than later.

Filtering your water in this way gives you a consistant benchmark- Full Stop!. The benchmark is the highest quality possible. so regardess of what country or state you live in & from what water source. It takes away the unknowns.

Di is the final absorbtion resin stage in a given RO system. Reverse Osmosis is the process of stripping the pure water molecules from the source, hence why it has a membrane.
Ether one or the other isn't the advise id be giving. All your going to do it spend money quite freqently in new DI based on your TDS water source coming in. The crapper the water source, the quicker it will become exhausted.

If your going to do that exclusivly, then at least run inline prefilters & carbon to extend the life.

Clean water like that is like a sponge for its environment, so stop thinking 1 dimensional peeps. If you want to drink it, add oxygen, if you want it to use it for your fish, add it to the environment thats already meant to be stable. This is also where the plus helps with creating an equilibrium in a sump, instead of straight in the display. not to mention where putting thought into your chosen system will allow for less water changes as a whole, not more!
PH of RO is already in the range, so its not the water that keeping it stable is it! All the crap you add to the water already, plus what ever you deploy as a buffer already is still there.

If you want constant quality water, go RO/DI, if your happy to drop quality & dip into potentially the unknown, then thats your choice to! Its really as simple as that!

[Tommo]

Thanks for everyone's comments :)

Well seems i have an RO/DI unit.
This is what i am going to do :)
"I like Jothy's idea "
A 50/50 mix of Tap water & RO.

Now , next question.

Getting the P.H down to 6.7,
What's the best meathod ?

[ILLUSN]

If you use a 50 50 mix i think your ph will naturally sit between 6.5 and 6.8 without any modification

[Tommo]

That would be great if it did that :)

But if not , whats the best thing to lower it ?

I used to use P.H down , but i am just wondering if there is a better way , maybe peat moss ?

[rex82]

peat moss is good, but being a show tank you may not like the tannins, you can drop it using hydrocloric or phosphoric acid in your water when you age it. are you trying to breed the discus? i would just leave the ph to its own devices after the mix if it's a show tank. i just read that it will be planted, just leave it be imo. if you use co2 it gets even more complicated but i'll leave that for someone more knowledgeable.
HTH

[Tommo]

Thanks for your advice ,
I have had a planted tanks before
And will be using Co2 .
Just trying to get people involved ;)

I will not be keeping Discus ,as they do not interest me anymore.They are a nice fish though.

[swampy1972]

Thanks for your advice ,
I have had a planted tanks before
And will be using Co2 .
Just trying to get people involved ;)

I will not be keeping Discus ,as they do not interest me anymore.They are a nice fish though.

Being new to Co2 myself I've invested in a Ph controller to take the guess work out of it. Hopefully relatively set and forget... :? It's a Weipro 2010 from EBay for under $100. Not 'top-end' by any stretch but I've heard good things about it.

Have you tested the water straight from your tap yet? This will give you the best indication of what the likely outcome will be re: water parameters and what you're likely going to have to do to adjust it, if at all.

I'm pretty lucky here having soft water at about Ph 7.0-7.2 straight from the tap so I don't need to do much. The small amount of tannin that's left in the DW brings the Ph down to the mid 6's. Hopefully yours is similar.

Best of luck. ;)

[Tommo]

I have been to lazy to test the tap water LOL "i'll get round to it ;)"

I also use a controller for my co2 , milwaukee sms120 , a good unit never failed yet :)