[freshreef]

assuming all other tank parameters are the same - do u think that in a softer water ill need less watts per gallon?

 

[Sir_BlackhOle]

hmmm.....I dont think so, although i dont know for sure. anyone else want to chime in?

 

[Bert H]

I can't imagine why you would.

 

[Rex Grigg]

Why would you think that?

And I can tell you it's not true. My normal tap water has no hardness and has a pH below 7. And it takes just as much light to grow plants in that water as it would in harder water.

 

[gnatster]

I can't see any reason at all where softer water would require less light to achieve the same results. It's not like the hardness of the water effects how the light is dispersed at levels of light or hardness that we commonly use.

 

[Gomer]

well..if you generate soft water by leeching out tannins and other acids (black water), then you could end up needing MORE light

 

[ShaneSmith]

I highly doubt light will be interrupted by hard water. Unless the Hardness of the water reflects more light

 

[Gomer]

I highly doubt light will be interrupted by hard water. Unless the Hardness of the water reflects more light

another "well..."

well, if your water is SOOOO HARD that you are precipitating calcium, then I guess it would require more light ...but I think you would have other things to worry about LOL

 

[Edward]

mor b
may have a point. I never seen any research done on this, but lets not forget, the weaker the solution the easier it is for plants to absorb nutrients. Easier means less light energy requirement to do the same job.

Edward

 

[ShaneSmith]

Where did you learn the weaker the solution the easier it is for the plants to absorb nutrients? Does that obtain to anything in the water? if so my plants must be athelets.... there is tons of stuff in my water they work like horses.

 

[freshreef]

thanks all,
i asked that because i try to understand the logic behind amano tanks. his gh and kh r about 2 and most of the time he uses only 0.5w/l only.
i thought that in harder water like gh15-20 ill need more light and fert to compensate for the hard water.

 

[Rex Grigg]

I think that if you study a bit more you will find that his tanks average well above .5 w per liter.

 

[plantbrain]

I would not place too much credence on those published parameters.

Soft water has less nutrients than harder water, at higher light, I suppose one could argue that harder water will grow plants better if there is a limitation of carbon/CO2, since there is more total DIC carbon in the harder water so the plants could have access to the KH, the HCO3 portion of the water.

But if you have plenty of CO2, harder water will still provide more in the form of GH.

At lower KH's, the activity of many metal cations(eg Copper) is more toxic and also more available. Generally this level becomes an issue around 150ppm of (8-9 degrees) in the literature.

But if the traces are dosed regularly to excess ayway, this is not a biggy.

Under natural conditions and under generally limited conditions in the water column, yes, then it can become an issue.

So generally softer water will use/need less traces. How much? Not sure.
I doubt that much.

Better aherenace to CO2, KNO3 dosing etc will get you much further than softening your water. Also sikmple stuff like water changes and good pruning and plant fluffing etc.

If you have harder waters, adding a tad more Trace is not going have negative effects.

So what do you gain from the hassle of making the water so soft?
Nothing significant.

Try it and see for yourself.

Regards,
Tom Barr

 

[jerime]

Sorry for barging in but Tom Barr wrote :

So what do you gain from the hassle of making the water so soft?
Nothing significant.

Arn't there any certain plants that need softer water or that will grow better under softer water conditions?

 

[plantbrain]

I suppose if you want to "believe and have faith" there might be some, I've never seen anything definitive after growing xcklose to 250 species of plants.

Generally I've had much harder water than many. I did fine and got the plants to the level of Amano's pics.

So if I can grow it fine in hard water...................is it that significant and can you really call it a soft water plant?

I've still had that open question for the last oh 7 or 8 YEARS now that ask is there a soft water plant?

No one's came up with any thus far. Been awhile. I've looked for them, I'm getting tired of looking though

The same can be said for Allelopathy, Cables, "high" light plants , red plants need more Fe, or X causes algae........ etc

If you fine one, you let me know.
Hehe, till then, I'll stick with the generalization, there are no soft water plants.

I will say a few species do appear to do better in slightly lower KH's, GH's, but 3 KH and 5 GH will grow anything extremely well.

Traces are more toxic/available(depending on how you look at it) when the alkalinity is low.

I chuckle when someone says Hairgrass, Gloss or such and such plants prefers or likes soft water.

I've grown a ton of species at very high GH's/KH values and seem to have done better than those with less KH/GH.

I'm not out here lying to folks, leading folks astray

Most just need to re evaluate their CO2, Macro's and Traces and go through their routines and picking/pruning methods a few times to get it right.

If you want a "less is more" or "add just enough approach", start with just enough lighting.

By the same token, you can fine the upper ranges by adding a ton of light and chasing that.

You guys will figure all this out later on if you are in the hobby for the long haul and play around with stuff.

Regards,
Tom Barr

 

[freshreef]

thanks tom , just to make sure
when i talk about hard water im talking gh over 20 and kh around 15

 

[plantbrain]

My tap was GH 24 and KH of 11, I doubt that difference is going to make a difference.

Regards,
Tom Barr

 

[tsunami]

but 3 KH and 5 GH will grow anything extremely well

Of course those values can. That's pretty darn soft. I don't think you can make such a generalization using those numbers.

Try growing Tonina sp., Eriocaulon sp. (especially the low rosette forms like Goias and Mato Grosso... see Plant Finder for photos), and others in hard water (GH 12+, KH 10+). I'd actually be very interested in hearing about those results.

I haven't had too many problems with growing certain plants in hard water, but I find plants to be significantly easier to grow when the water is softer. One of them is Rotala macrandra.

Notice the sickly, dark stem in the upper right hand corner? That's my R. macrandra 'broad' in GH 14, KH 12 or so:

Nutrient levels were NO3 10 ppm, PO4 2ppm, 20ml/week Flourish in a 20g.

Now, notice the difference with my Rotala macrandra 'broad in GH 5, KH 3:

Nutrient levels were NO3 5 ppm, PO4 0.5ppm, 20/ml week Flourish in a 55g.

Carlos

 

[plantbrain]

I said "anything" in those parameters(GH 5, KH3) and made a generalization about hard water(thereby leaving a few plants out).

Few grow Tonia and Eriocaulon sp, but R macrandra is commonly grown. It's done better for me and others in softer water(3KH/5GH) and I will say a few plants do grow easier in "softer" water. The question remains as to why, but I'd bet it has to do with metal trace cations at lower KH.

Uptake or translocation/transport issues.

On an ecological scale, when the water becomes softer(Rainy season), the plants better grow or else they will be out of the photic zone.

But 50ppm or less I do not think there are any plants that have issues that require this. I've found plants growing in places with no KH/GH, but these do well at moderate soft water also.

Around 250ppm of alk, the traces become more difficult for plants to take in and also when we treat with Copper etc, this inactivates it and we must use the chelated forms.

I'm leary about comparing one tank to another, but R wallichii, R macrandra, Eustralis seem to do much better in softer water.
I have not tried the two Eriocaulon sp you mentioned, but have grown the other Eriocaulon sp at harder water.
Nor have I tried Tonia at hard water.

But to suggest that you need less than 3KH I think is wrong and that's why I said anything.

Still with some 300 available species, only a very few seem to do better with moderately softer waters. I have not tried Tonia nor Eriocaulon sp in my tap water here( It's back to hard again).

So I will see if the plants do not grow well.
And I did well with Rotala's in Marin with KH of 5.5 and Gh of 9.

Still, I'd like to do more controlled work to see and figure out more about why this influence causes certain plants to act funny.

But as to the orginal issue, that we need a KH less than 3/GH5 etc.
I will say I have never found a plant that needs less than this the thrive fully.

I certainly would not rush out to get nor suggest someone needs a RO unit.

This level maybe higher and how much I'm not certain, I have not done incrementally by adding more KH/GH to find out, just used what my tap water had in it as conveinence and others/clients that had softer water.

Regards,
Tom Barr

 

[Edward]

Here is my experiment with soft and hard water,
Hemianthus callitrichoides

I. Aquarium, GH < 1, KH < 1, TDS 50 uS micro Siemens

II. Aquarium, GH < 1, KH < 1, TDS 50 uS micro Siemens

III. Aquarium, ... and here is the trash at GH 16, KH 18, TDS 950 uS micro Siemens