Question on RO water versus tap water

[mom2reds]

My LFS guy tells me that i will be able to grow more types of plants if i use RO water because I could adjust the PH better and that our local tap water is to hard to grow some of the more lace type plants.
My ph of my tap water is 8.0 the hardness is around 250 the alkalinity/buffering is around 240 nitrite is 0 and nitrate is 20 I curently have two 10 watt screw in cf lights and have two java frens and a wendtii red crypt. That are all doing well I just use flourish excell.
Would I be beter off if i use RO water or not? Oh i have ECO complete as my substrate.

Thanks Tess

 

[dapellegrini]

If you use RO water you will have to re-dose for the KH/GH and NO3 that you would be removing. If you really have 20ppm of NO3 in your tap water, you city is in serious violation of EPA water quality standards. The maximum allowed level is 10ppm. Also, I do not believe that RO water will change your pH at all.

Anyhow, RO is typically a waste of time in FW aquariums. You do want to drive your pH down and the best way to do that would be with CO2. Perhaps a quick DIY setup. Way cheaper than RO/DI and you will have better plant growth. Whatever you do, don't try chemical buffers to play with your pH.

My tap is around 8.0 pH, with about 120ppm of KH (alkalinity), 200+ppm General Hardness. I use CO2 to drive the pH down to 6.8 and I have great plant growth:

http://www.aquariumadvice.com/viewtopic.php?t=88786&start=50

250ppm of KH does sound kinda high, but I don't think RO is a good solution for you.

 

[Shubunkin01]

Sorry, don't mean to threadjack, but how does C02 lower the ph? (I ask because my ph is around the 8.2 mark)

Thanks
Shubunkin01

 

[dapellegrini]

From one of the stickies (see #4): http://www.aquariumadvice.com/article_view.php?faq=2&fldAuto=41&page=3

 

[mom2reds]

The 20 ppm of no3 and the other parameters are after it has been in my tank for about two hours after a 50 % water change if that makes a diference. Thanks for the reply. I have anouther question do you think that i would be able to grow medium light plants?

Thanks Tess

 

[Shubunkin01]

Thanks!

 

[rkilling1]

FWIW, some plants do perfer soft water over hard water, but the majority of the plants that you find in mom and pop shops don't have a problem and I would even say love harder water.

HTH

 

[dapellegrini]

RK - Doesn't RO take you down to ZERO? Perhaps if you did a 50/50 mix of RO and tap you could take your KH / GH down...

Tess - How big is your tank?

 

[rkilling1]

yes RO water will remove the majority of the elements from the water, so you have to add them back in. Seems like a waste of money if you ask me. If you remove most of the buffers from the water and do not add them back in, your water is subject to pH swings and that is not good for the fish, let alone your plants need the nutrients.

EDIT: I guess I should of said changes in KH are not good, instead of pH.

 

[mom2reds]

my tank is a ten gallon

Tess

 

[dapellegrini]

On the lighting question, you could probably get away with some medium light plants... Do you anything specific in mind?

 

[czcz]

Doesn't RO take you down to ZERO? Perhaps if you did a 50/50 mix of RO and tap you could take your KH / GH down...

Yes, and mixing tap with RO is a very easy way to lower KH while keeping GH. While Ca and Mg are nutrients, it's been shown time and again that low and stable KH can aid many plants, especially Tonina, Eriocaulon, and some Rotala sp.

When most people talk of soft water plants, it's in regards to KH, not GH. Tom Barr/Plantbrain is one who grows plants in low KH while dosing Mg and Ca (GH). Still others will grow in low to no KH while targeting ratios of Ca and Mg. Fwiw, my preference is to dilute 50% of my moderate hardness tap with 50% RO. This is simply easier for me than reconstituting pure RO.

HTH

 

[rkilling1]

When most people talk of soft water plants, it's in regards to KH, not GH. Tom Barr/Plantbrain is one who grows plants in low KH while dosing Mg and Ca (GH). Still others will grow in low to no KH while targeting ratios of Ca and Mg. Fwiw, my preference is to dilute 50% of my moderate hardness tap with 50% RO. This is simply easier for me than reconstituting pure RO.

HTH

This is something that I am still learning also. There is so much misinformation out there. (some that I continue to spread ) I have quotes from Tom, where he has run tanks with no KH like you mentioned and only buffered them to find out what the CO2 levels where and then unbuffed them. So I guess RO is fine, like you said, as long as you add in Mg and Ca , which are macro nutrients.