Water question

[Thever]

Hi,

I run a 10 gallon planted shrimp(RCS and Amano)tank. I've been using water from the tap-which is from a water softner. I did some testing today and heres what Ive got.
Tap - GH-3 or 4 , KH-13, PH-7.6

Non softened tap-Gh - 30, KH-13, PH-7.6

So...what water should I use? Combination of both? Things seem ok w/ the softened water, but seems people dont advise that. Thanks

Kevin

 

[neilanh]

I think in your case it's fine. Since your non-treated water is so hard, the softener I think is actually beneficial in your case. Your kH is still quite high, but if it's working I wouldn't mess with it.

 

[Thever]

Is there any reason why I would want to lower my kh? I thought kh was a good buffer against ph swings...or is 13 more than enough for that?

Thanks
Kevin

 

[jsoong]

you wouldn't want to reduce the KH. you are correct in that it buffers against pH swing. You have a reasonable pH, so I would leave it at that. <You prob have an ion exchange softener ... those would only reduce the GH but not KH.>

The only thing I would question is the softened water's GH of 3 or 4. Since you are keeping shrimp, they do need some Ca to build their shell. I don't keep shrimp so I don't know if that level is enough. <It would not be enough for snails.> Also, if you have a Na ion exchange unit, you might have high Na level in the softened water, which plants don't like. <If you use a K exchange, then the K is good for the plants.> But if everything is looking good, I wouldn't change from what you are doing.

 

[Thever]

Thanks for the info, Im not sure what the type of softner we have is, plants look....ok. My riccia looks the best, other things dont look so hot, which could be a dosing problem on my part, I'm still getting the hang of that.(Leaves of plants kind of look like they are melting away,yellowing leaves on helferi) -I'm thinking lack of potassium

Just found my manual to the softner...says that the hard water passes through the resin beads which hold the calcium and magnesium ions in exchange for sodium.

As far as dosing goes, I can dose KNO3,K2SO4,CaC12+2H2O,KH2PO4, and a trace

 

[jsoong]

Then you have a Sodium (Na) ion exchanger.

GH of 30 = 550 ppm. After your exchanger is done, you would have 1000 ppm of Na or about 1g per l of Na. This is equal to you adding 0.1% salt to the water. <Granted, you are only adding the Na, not the Cl ... and Cl has more biologic activity.> At any rate, this is a lot of Na and might be bad for some plants. <Not really good for drinking either ... that's why people having heart diseases/ hypertension are advised to get a potassium (K) ion exchanger.>

Your plants might well be wilting from the salt content. From what I can recall reading about salt tolerance of plants, about 1/2 of the aquarium plant species die at 0.2 or 0.3% salt. It might be worthwhile to try using water from before the softener. <Or use a K ion exchanger ... you can then skip dosing K for your plants!>

EDIT: Woops .. a mathematical conversion error ... the final salt concentration is around 700 ppm or 0.07% (not 0.1%) ... advice unchanged!

 

[Thever]

Lovely.....if it isnt one thing...its another. It does say something about using potassium chloride, but may require adjustments...no details.

So...my choices are
No softer- HARD water , much lower NA content
softer - soft water - salty water

I have rcs and amano shrimps in a planted tank....which would be better? I'd rather not think about a ro unit-unless it was CHEAP, spent enough money on this fish business

 

[jsoong]

If you can find out how to adjust your unit to use KCl, that would be the best!

Maybe you can try 50:50 mix as a cheap alternative.