[Edward]

RO is fun

I use RO for several years and I like it. It gives me the option to control all the elements.
With tap water we never know what is going on. There could be ions of high concentrations that we have no test kit for.

Last time I tried tap water the snails looked dead for a week.

There is no issue with the operation cost. The whole system needs one $3 10 um cartridge and one $10 carbon cartridge a year. The cost of running water is $1 for 60 gallon of pure water. The main cartridge works for 5+ years.

This mix I use, is to recreate balanced levels of Ca2 and Mg2. This is used for a long time, since DI was introduced to breed Discus.

3.0 g CaSO4
1.0 g CaCl
1.5 g Soda
1.0 g MgSO4

Final concentrations can be tested by TDS meter for breeding or by regular Calcium test kit for growing aquatic plants.

Thank you,
Edward

 

[Edward]

gpodio,
good to hear you like it.

The TDS is a great thing to have, but the DI is not necessary for planted tanks and for drinking, as it makes water really unstable. Also the container may get infected with microorganism at one time. UV sterilizer makes it perfect safety combination.

For drinking use, filtration over coral makes it valuable add on. One day you get bored by the plain taste of RO, 1/4 teaspoon of Sea salt per gallon makes excellent taste and healthy source of drinking water.

Thank you,
Edward

 

[Edward]

Edward,

I'm curious why you add CaCl and CaSO4.

I used to breed discus before plants took all my free time. First, there was an ion exchanger DI, made of cati and ani to purify the water. I still have HCl hydrochloric acid and NaOH sodium hydroxide at home. These were needed to regenerate the functionality of the DI. From this experience, I know how unsafe DI is to maintain and to drink.

The water purity produced by a DI is 10x better then the distilled and 100x then the RO, but it doesn't matter for the plants.

DI, cati/ani 0.1uS TDS
Distilled 1.0uS TDS
RO 10uS TDS

Back to your question, waters stripped of minerals need to have restored basic living conditions for the fish eggs to develop and for the fry to survive. It's all about balance of salt ions, causing osmotic pressure on living organism. Balance of Ca:Mg:Na:Cl. This is why I am still using the discus breeding formula to grow aquatic plants. If it's good for discus, must be good for plants. And it works just fine.

It's a mix of dry minerals:
3.0g CaSO4
1.0g CaCl
1.0g MgSO4
1.5g Soda

For discus keep adding until desired conductivity uS TDS is reached. For plants until measurable Ca2+ .
For an automatic continues RO water change, this kind of dosing makes it difficult to keep stable levels. So I started experimenting with dolomite as Tom Barr suggested. It is a mineral made of CaCO3 calcium carbonate and MgCO3 magnesium carbonate. http://mineral.galleries.com/minerals/carbonat/dolomite/dolomite.htm . This dolomite might replace the discus formula for plants if it proves to be working.

Thank you,
Edward

------------
2005 01 05
Dolomite increases TDS and KH too much. Ca and Mg is there, but the KH is out of control.

 

[Edward]

Hi Jason

There is no point using DI for planted aquariums. The RO cartridge already removes 90 – 99 % of all dissolved elements. Here is how it works:

500 uS TDS very hard water
300 uS TDS usual tap
10 uS TDS RO
1 uS TDS distilled water
0.1uS TDS DI

RO water does not have any GH or KH. You need to either mix it with tap water or add Ca, Mg and KH. Plants need Ca and Mg for healthy growth.

Edward

 

[Edward]

Hi robitreef

There are two TDS systems, ppm and uS.
uS = 2 x ppm
ppm = uS / 2

160 ppm = 320 uS

Edward