Rain water

[Matuva]

Hi there

for the very first time, I collected rain water. I found a TDS of 3 and a KH 0 !!

I didn't think the values can be that low! I have to say I have never used rain water before.

Can  use it "as is" or do I absolutely need to tweak this water before using it.

As for rain water, this one has been collected by placing container in the yard under heavy rain. Is it safe using water coming from the roof?

[jayc]

3 hours ago, Matuva said:

Hi there

for the very first time, I collected rain water. I found a TDS of 3 and a KH 0 !!

Yes, that's normal for rain water. It is the closest to RO water. Rain water is pure water. It collects "stuff" when it falls. That is what you might see in that TDS 3 reading. Small dissolve-able minerals that was in your bucket would add to the TDS 3 reading as well.

 

3 hours ago, Matuva said:

Can  use it "as is" or do I absolutely need to tweak this water before using it.

You can use as is, IF you are topping up the tank from evaporation.

But if you are doing a water change, you will absolutely need to remineralise it. Use something like Salty Shrimp or my DIY mix with Calcium/Magnesium.

Again, treat it like RO water. 

Remineralise if you are trying to reach a certain target in TDS.

Just a note: Rainwater can cause the pH to drop significantly. I have rainwater only aquariums where pH have dropped as low as 4.8pH. Rainwater has absolutely no buffer to keep pH at a steady level, pH will keep dropping. This can be an issue if you are not monitoring it closely.

 

3 hours ago, Matuva said:

As for rain water, this one has been collected by placing container in the yard under heavy rain. Is it safe using water coming from the roof?

It depends on what your roof is like?

If it's rusty, has a lot of bird poop, or painted, then I would be cautious using it.

If your roof is cleared of bird poop, and is made of terracotta tiles or plastic, then it's probably safe. But it's always a good idea to not collect the first 10 minutes of rain from the roof to make sure contaminants are washed away in that first few minutes.

If your roof and gutters have organic matter, like leaves and twigs, it's not so much of an issue, BUT it will increase TDS, maybe to around 10-15.

I use a lot of rainwater for my Killi fish and South American dwarf cichlid tanks.

 

[Matuva]

Thanks Jayc :)

I'm pretty sure I have a bottle of Seachem equilibrium stored somewhere in the house. The only problem is to remember where I keep it stored...

Other than that, what ratio of Calcium and Magnesium would you recommend me to add per 10 liters?

Edited March 29, 2016 by Matuva

[jayc]

1 hour ago, Matuva said:

what ratio of Calcium and Magnesium would you recommend me to add per 10 liters?

Well, it should say on the bottle of  Seachem equilibrium, if that is what you are using.

Otherwise, check TDS readings as you add a bit of Equilibrium slowly.

 

Seachem equilibrium ingredients:

Soluble Potash (K20)	23.0%
Calcium (Ca)	8.06%
Magnesium (Mg)	2.41%
Iron (Fe)	0.11%
Manganese (Mn)	0.06%

Edited March 29, 2016 by jayc

[Matuva]

I also read on anther place that you can use Baking soda and Epsom salt to remineralize.

Have you heard about that , and know about what dose to use per liter or per 10 liters?

Or, should I just mix 50-50 rain water with tap water?

[perplex]

Jayc did a DIY for remineralisation, i personally use this, its far cheaper, and you can change values very easy if you know what to do.  link below

 

 

Edited March 29, 2016 by perplex

[jayc]

10 hours ago, Matuva said:

Baking soda and Epsom salt to remineralize.

Have you heard about that

No, that's just wrong.

Epsom Salt is fine, as it is just Magnesium sulphate. 

But Baking soda is not right. That's sodium bicarbonate. It will send your KH and pH soaring sky high.

Besides that, baking soda is used for ... baking. It usually has a reaction agent (usually something acidic like cream of tartar) to activate the rising agent. Bi Carb Soda on the other hand is sodium bicarbonate without the cream of tartar. Bicarb Soda is usually used to raise the KH and pH.

But if you don't have any remineralising products on hand, then mixing rainwater with tap water is a safer method. But what ratio to mix will need you to experiment. My tapwater is different to your tap water. To get pH 7.0, I need 75% rainwater to 25% tapwater in a 10L bucket (for example). 

 

3 hours ago, perplex said:

Jayc did a DIY for remineralisation

Thanks for the plug ?