RO Beginner

[Aburas10]

Hi everyone, I'm thinking of switching to an RO or RODI system. My tank (22 gal rimless) is cycled and has been running for at least six months. I change my water 25% 1x a week and this is the reading the day before a water change. I do not have a TDS meter yet.

Ammonia- 0
Nitrites- 0
Nitrates- 5-10 range
pH- 8.0-8.2
gH- 340.1 ppm
kH- 107.4 ppm

I tested the aquarium water and the tap. The tap readings are:

Ammonia- 0
Nitrites- 0
Nitrates- 5
pH- 7.4
gH- 179 ppm
kH- 89.5 ppm

I have a consistent routine, I leave out and condition my water several days before adding it to the tank (I change on the same day weekly). I was completely unable to keep shrimp- I had deaths after water changes (found out my old home has copper pipes). I tried multiple remedies with the shrimp but had no success. My plants are less than ideal even though I use ferts as directed. I am currently stocked with pygmy cories and otos. I have lost 2 of the cories, and one of the otos so far (eating supplemental food was not an issue). So with all that being said, the only thing I haven't tried is changing my water source.

If I am on the right path with my train of thought, I have RO questions. I don't need much water per week so I am looking at the RO Buddie. I would like to use all RO water and no tap, especially because I'd like to keep shrimp and my understanding is that the RO should remove any trace copper. I have read that it is necessary to remineralize RO water (I'm pretty lost on this subject).

What are your thoughts? I've been doing a lot of reading but there's always conflicting information out there. Any help is appreciated!

 

[Chanyi]

Per 1 US Gallon:

0.386 Grams CaSO4 - 30ppm Ca, 4.2 degrees GH

0.384 Grams MgSO4 - 10ppm Mg, 2.3 degrees GH

0.135 Grams KHCO3 - 14ppm K, 1.0 degrees KH



Should yield:

6-7 degrees of General Hardness

1 degree of Carbonate Hardness

7.1 – 7.2 pH

Mix up in advance of your water change. You can adjust the Ca and Mg needed for your specific needs, but those numbers worked very well for planted shrimp (neo) tanks.

 

[Aburas10]

Thank you! A few more questions-

Did you do RO water only in the tank?
Where do you buy the Ca, MG, Kh?
Do you add anything else to your water besides the minerals?

Thanks again!

 

[Chanyi]

Did you do RO water only in the tank?

Yes, 100% RO water.

Where do you buy the Ca, MG, Kh?

GLA, Amazon, Brewing supply stores, Drug stores.

Do you add anything else to your water besides the minerals?

I add fertilizers along with those stated minerals after a 50% or larger water change.

15ppm NO3 using KNO3
5ppm PO4 using KH2PO4
3ppm K using K2SO4
0.15ppm Fe using a custom micro nutrient fertilizer blend
1mL plant growth / stress hormone (not available to the public)

 

[Aburas10]

Thank you for how specific you've been. I struggle with the concept of water chemistry as a whole.

 

[Chanyi]

Thank you for how specific you've been. I struggle with the concept of water chemistry as a whole.

Go play around on this website:

1) Enter your amount of water you change into the "My aquarium is" text box
2) Select the DIY bubble
3) Select your compound you will be using (CaSO4.1/2H2O for Ca / MgSO4.7H20 for Mg / KHCO3 or K2CO3 for KH)
4) Select the dry dosing bubble
5) In the "I am calculating for" drop down menu, select "dose to reach a target"
6) Enter in the target you are after: Ca - 30ppm or Mg - 10ppm or KH - 1.0 degrees
7) Let it auto round and select calculate

You'll be left with all the info you need to dose your amount of water to your target level. I would invest in a $20 jewelry scale accurate up to 0.001 grams that comes with a calibration weight + the ability to be calibrated. Weights are what we need to use to ensure consistency, otherwise you'll be causing KH swings which are fish / shrimp deadly. Don't do as I did and start with the micro measuring spoons, I quickly found out the hard way my dosing was absolutely way off from what I was trying to do. The scale is perfect for measuring out many other fertilizers, and you can track food consumption as an added experiment to your tank / estimate NO3 production.