Is RO/DI Water Conditionder needed?

[bry1105]

A few weeks ago I began using RO/DI water and suddenly today 2 of my fish have died. Is it really necessary to buy RO/DI water conditioner, or it is just another way for manufacturers to make money? If so, what kind is good? I have freshwater aquarium salt by API, would that work?

 

[librarygirl]

Why are you using RO/DI water? Are you using 100% RO/DI or cutting it with tap water? If you're using solely RO/DI water you need to add minerals. Pure RO water is like distilled water; it has nothing in it and the fish need the minerals in the water. You'd have to add something like Kent RO Rite or Seachem Replenish, otherwise the water probably isn't too healthy for the fish. Pure RO/DI water may not need dechlorinator but it wouldn't hurt to add it and if you're using it with any tap water you'd have to add it.

 

[adeebm]

Yikes, pure RO/DI? Like librarygirl said, you need minerals. RO/DI has 0 TDS, which means your fish won't be able to osmoregulate among other things. It's not surprising that your fish died from it. If you want to use RO, you do need a conditioner. Why are you using RO in the first place? It isn't necessary for the vast majority of fish and will only cost you money and trouble.

API salt won't work btw, it's basically just table salt.

--Adeeb

 

[Phranque]

OMG!!! Did you check your Ph? Remember, the RO/DI filter removes EVERTHING from the water. Not only do your fish require some of those minerals, but, more importantly, so does the water itself. You have to maintain a certain KH (hardness buffers) to maintain a stable Ph.... without these, your Ph is likely taking wild swings, if not completely crashing.
I blend approximately 35% tap / 65% RODI to maintain a KH DH (degree of hardness) of about 5 to 6. If you are going to do this, you need to pick yourself up an API GH/KH test kit. Test the hardness of your tap water, and then calculate what percentage you need to add to your RODI to get the desired results. My tap water is KH 16, so cutting it by 65% with RODI gives me a KH 5.6. The nitrification process neutralizes & consumes some of the KH as Nitrates build, so testing prior to PWC's is essential to know what blend is needed to replentish your KH if needed.

Article on GH & KH:
http://e2.aqua-fish.net/show.php?h=aquariumreverseosmosis
http://e0.aqua-fish.net/show.php?h=aquariumwaterhardness

 

[bry1105]

You guys make it sound like using RO/DI water is a stupid idea. Just so you know, Im using it because the water here is EXTERMELY hard and the phosphates & silicates are giving me diatoms. Tap water isn't great for fish.
You're probably right about the ph swing. That was my first guess too.
I was thinking about using Kent RO Right, but now I think it's pretty obvious that I need it.

 

[MrPillow]

We're not saying using RO is a stupid idea, we're saying that using it without adding essential nutrients and elements back into the water is a death sentence for any organism living in it. Plenty of us use RO, you just gotta remember that it isn't safe for the fish without treatment first

 

[Phranque]

You guys make it sound like using RO/DI water is a stupid idea. Just so you know, Im using it because the water here is EXTERMELY hard and the phosphates & silicates are giving me diatoms. Tap water isn't great for fish.
You're probably right about the ph swing. That was my first guess too.
I was thinking about using Kent RO Right, but now I think it's pretty obvious that I need it.

Using RODI isn't a stupid idea.... just need to know what you're doing (after all, isn't that why we're all here ) .

I used RO Right for a little while, but IMO, a waste of money. For my blend water, I inserted a tee with a valve in the line after the water passes through the prefilters, but before it hits the RO membrane. That way, it passes through the sediment filter & the two 0.5 micron/carbon filters, neutralizing any chlorine & ammonia and filtering out some of the larger junk. I still use conditioner as a safety factor, but this set-up works great....

 

[bry1105]

We're not saying using RO is a stupid idea, we're saying that using it without adding essential nutrients and elements back into the water is a death sentence for any organism living in it. Plenty of us use RO, you just gotta remember that it isn't safe for the fish without treatment first

Yeah, I'm realizing that now. Im going to get some Kent RO Right today before I lose anymore of my fish.

For my blend water, I inserted a tee with a valve in the line after the water passes through the prefilters, but before it hits the RO membrane.

That is a nice setup, but I live in an apartment so I don't have the luxury of running plumbing anywhere I want. I'll have to remember that for the future when I do have a house of my own.