RO water and remineraliser for Pygmy Corys

[lilirose]

I'm new to this forum. I have a 90 liter tank, heavily planted with a thick sand cap over organic soil, with 10 healthy and happy young Corydoras Pygmaeus. I am crazy about the little guys. They share their space with several large Amano shrimp and the whole tank seems to be doing very well.

My question is about RO water. My tap water is extremely inconsistent- sometimes it's fine and soft, sometimes it's inexplicably hard (as measured with a TDS meter), sometimes it comes out of the tap reeking of chlorine, sometimes it is literally brown and smells bad. Obviously this is not at all suitable as I have a Neocaridina shrimp tank as well as the aforementioned 90 liter, so I bought a RO unit. People keep saying that using pure RO and a remineraliser is too much hassle but I think dealing with crappy tap water that contains heaven knows what is far more of a hassle.

In any case I've been using JBL Aquadur as my remineraliser and I take the water to a GH of 5 and KH of 3, which seems appropriate for dwarf corydoras. However I've read elsewhere that Aquadur has too much sodium and I'd be better off using something else. Remixing tap water is not an option here.

Can anyone recommend a good, safe remineraliser? My little corys seem to be doing fine but I want only the best for them and I'm hoping they will eventually spawn.

[Bas Pels]

Regardess further processing, in case you use RO water you will need further processing before you can use it safely in a tank.

Obviously I have no clue about how long all the different watertypes are on the same tap, but I would assume it is possible to collect some good water, and mix this with the RO water. This owuld safe you a lot of hustle. And money

[lilirose]

Thanks for taking the time to respond, Bas Pels- I do appreciate it. Unfortunately my tap water is not safe (I won't even drink it myself) and I cannot use it at all in my aquarium, as I explained at some length already.

I live in an extremely rural part of Ireland and water quality issues are very common in this country. I'm not sure where I could easily collect some "good water"- I have no clue what is in my tap water (the water company will only tell me "it's perfectly safe" and nothing more) and I am not okay taking risks with my livestock for the sake of convenience, which is why I asked about remineralisers.

Again, remixing tap water is absolutely not an option with my water supply. I also, obviously, know that straight RO water is unsafe. I need a remineraliser.

Surely someone knows?

[dw1305]

Hi all,

......I live in an extremely rural part of Ireland and water quality issues are very common in this country. I'm not sure where I could easily collect some "good water"- ...........Surely someone knows?

I've used rain-water, in the UK, since the 1970s without any problem.

I've been lucky enough to travel through Tipperary town a few times, from what I remember it is very scenic with the hills to north and south, not very near anywhere and it must rain prodigiously, with the highest quality rain-water.

You can use the re-mineralising mix from <"James' Planted Tank"
(http://www.theplantedtank.co.uk/RO.htm)>.

Have a look at this thread on using TDS as well (from UKAPS (https://www.ukaps.org/forum/threads/oh- ... ost-560117)).

cheers Darrel

[lilirose]

Thank you so much for your response, Darrel! I'm a lurker on UKAPS and have noted your useful input there, I've learned a lot from you.

The rain here has been far less than usual the past year or so, in any case isn't it essentially RO in that it also needs remineralised? As I already have the RO unit, I don't mind using that, my roses and fuchsia do love the waste water produced.

The planted tank mix you linked to sounds spot on, this is exactly the info I was looking for, cheers for sharing it with me!

[dw1305]

Hi all,

Thank you so much for your response, Darrel! I'm a lurker on UKAPS......

I post on <"Apistogramma Forums https://apistogramma.com/forum/">, <UKAPS https://www.ukaps.org/forum/> and PC, mainly because they are forums with strong moderation, a knowledgeable clientele and a reasonable level of debate.

I really want people to keep planted tanks, not only because I like plants, but because it makes fish keeping so much easier.

........ in any case isn't it essentially RO in that it also needs remineralised? As I already have the RO unit, I don't mind using that, my roses and fuchsia do love the waste water produced.......

Yes, your rain-water will be essentially RO. I would re-mineralise it. I'm lucky and can use our tap supply (good quality hard water from a deep limestone aquifer), if I didn't have that as an option I'd use the "Planted Tank" mix.

cheers Darrel

[Reindas]

I have not much to say about the subject of RO. I don't really know much just that people say is good. Can anyone tell the pros & cons.

Thank!

[Lycosid]

I have not much to say about the subject of RO. I don't really know much just that people say is good. Can anyone tell the pros & cons.

RO water is, effectively, extremely pure water, as reverse osmosis removes basically everything but the water. (Most RO units are actually RO/DI, at least the ones I've seen.)
Pros:
- You know what's in it (nothing)
- You can make it, with an RO unit, from tap water
Cons
- There's nothing in it, and fish don't like that (hence this talk of "remineralization", where minerals are added back in)
- RO units can be expensive, which is made worse when you have to buy remineralizers

In areas without air pollution rainwater is basically the same.

[Bas Pels]

One difference where RO water and rainwater are different is in dissolved gasses.

As lycosid explained, there is nothing in RO water, not even dissolved gasses. Therefore, RO water need 24 hours (perhaps less, I'm a chemist, but never used RO water myself) to get carbon dioxid and oxygen dissolved to saturation. Especially oxygen is a very slow dissolver.

Rainwater is already fully saturated with both of these gasses. One better compares rainwater with RO water after 24 hours of airating

The point is, using RO water fresh is bad for your fish, as it would lower the amount of dissolved oxygen a liter to dangerous levels.

10 mg a liter is possible, in clean water. Indirty it is less. Now imagine a tank, needing a waterchange of 33 %, and with a concentration of oxygen of 9 mg a liter. After adding 33 % fresh RO water, the concentration could be 6, lethal for many fishes.

[Reindas]

I see, so you get pure water that you have to prepare by adding what you just removed from it before using for freshwater. Now I understand what is does.

On the other hand since no one mention salt water I can only asume there are some benefits for it. But this is of no consequence for me I’m not planing on setting up a salt water tank in future, unless there’s a salt water Cory.

Thanks for explaining this to me.

[Lycosid]

I see, so you get pure water that you have to prepare by adding what you just removed from it before using for freshwater. Now I understand what is does.

It's mostly used for:
1) Really terrible water, where you need to take out lots of bad stuff and re-add only the good stuff (like in this thread)
2) Making water softer, by removing everything and then adding less of it back in. For instance, I mix 50/50 RO and tap water, making softer water for one of my tanks (the one with pygmy corys, in fact!). It is, as far as I know, the only way to make water softer that is both safe and relatively easy.

On the other hand since no one mention salt water I can only asume there are some benefits for it. But this is of no consequence for me I’m not planing on setting up a salt water tank in future, unless there’s a salt water Cory.

The salt water guys love it because salt water fish are all delicate flowers that die if they look at the wrong mineral, and RO water gives you very precise control over what's in the water.

[Reindas]

Now I understand why and when to use R/O water. So if the water I get from tab is ok, there’s no need to actually use R/O water, but if the water is bad or I just want to be sure the water is a perfect as it can be for the fishes in specific tanks then R/O water is the way to go.

Noted and added to the “ to be considered in the future” list.

Thanks for expelling it.

[Eddinson Panduro]

Hello everyone
With reference to water many use gallons of mineral water to drink that they sell in supermarkets

[Reindas]

It I had used mineral water to raise Triops. But I don’t know for the fishes, I guess it would be fine since we drink it.

This is a triops

[Lycosid]

It I had used mineral water to raise Triops. But I don’t know for the fishes, I guess it would be fine since we drink it.

We also do fine drinking chlorinated water, but fish don't want it in their gills.
I wouldn't be surprised if fish that like hard water could deal with mineral water, but soft-water fish will probably hate it.

[Reindas]

We also do fine drinking chlorinated water, but fish don't want it in their gills.

Of course not chlorinated water, as a rule I believe all water should be treated before adding fish, plants or any other living creature.