Reverse osmosis and safety of fish

[Nataliia]

Hello everybody,
I saw an earlier thread about reserse osmosis but decided to write my own because I have a different question.

The starting situation is as following:
I have to parachromis dovii aquariums that require a lot of clear water and frequent water changes. My dwell water even when filtered professionally isn't crystal clear. So I decided to buy a reverse osmosis system. I have just set it up and it seems to work well. I produces some 150L/min. The measured water levels after osmosis are about Ph-6, KH-1, GH-1.
In my aquarium water values are now about Ph-7,5, GH-8, KH-5.

My question:
Please advice is there any danger to fish when I am adding osmosis water during water change (usually 30% change) and then I correct the Ph/GH and KH values with correct doses.
Please advice do you use those products that aquarium shops sell to correct Ph/GH and KH or do you just buy them from grocery store (baking soda) and some crushed coral for higher KH?

 

[Nataliia]

Advice, anybody???

 

[ichthyogeek]

I use RODI water for my saltwater tank, and previously for a shrimp tank. I'd recommend pre-mixing the water so that it makes it to the parameters you want first, and then putting that into the aquarium, as opposed to adding the GH/KH boosters after you add in the RODI water. If you add in the RODI water first, that's going to swing the GH/KH first, and then you're going to swing it back to your target parameters, which will probably be stressful on the fish.

If you are new to remineralizing RODI water, I'd stick with using the products that aquarium shops sell (I'm a fan of SeaChem equilibrium and alkaline/acid buffers).

You say your well water is filtered professionally. Did you try running it through a sediment filter as well? Those are significantly cheaper than RODI units, and would help with making the water clear, while maintaining GH/KH levels of the well water.

 

[Nataliia]

Hello Ichthyogeek and thank you for reply!

My RO system is like this

purway | Osmoseanlagen und Trinkwasserfilter kaufen

Kaufen Sie Testsieger Osmoseanlagen ✓ Trinkwasserfilter ✓ Wasserfiltergehäuse ✓ Wasserfilter ✓ Brunnenwasserfilter ✓ Eisenfilter ✓ Rückspülfilter.

shop.purway.de

The reason I had doubts about the premixing is the following. If I put minerals in one of the filters then of course when the system is not in use then water just lays in that filter and absorbs the minerals resulting in higher concentration of Ph/KH/GH and when I turn on the system water starts to flow through the filter and in beginning the concentration of Ph/KH/GH is higher and more water goes through the less it absorbs the minerals and Ph/KH/GH lowers pretty much.
This is based on some testing I made.
Please tell me how does your pre-mixing work? Does it result in equal quality water or how do you control the process?

I was planning to start making water changes with this water and carefully add the minerals and make measurements in the end.
I noticed a typing error in my first message, the RO produces 150L/hour nor 150L/min.

I have a lot of filtration systems for dwell water and water parametres are good but still water isn't crystal clear but just a bit yellow. That's the only reason to try this RO system.
Sorry for bad English

 

[BIG-G]

Have you tried carbon block filters?
If other parameters of your source water are good, the carbon will be cheaper, easier to maintain and should remove the discoloration.
Dwell time may be a factor.
If so, then you could link a couple carbon filters in line to increase the filtration.

 

[ichthyogeek]

Hello Ichthyogeek and thank you for reply!

My RO system is like this

purway | Osmoseanlagen und Trinkwasserfilter kaufen

Kaufen Sie Testsieger Osmoseanlagen ✓ Trinkwasserfilter ✓ Wasserfiltergehäuse ✓ Wasserfilter ✓ Brunnenwasserfilter ✓ Eisenfilter ✓ Rückspülfilter.

shop.purway.de

The reason I had doubts about the premixing is the following. If I put minerals in one of the filters then of course when the system is not in use then water just lays in that filter and absorbs the minerals resulting in higher concentration of Ph/KH/GH and when I turn on the system water starts to flow through the filter and in beginning the concentration of Ph/KH/GH is higher and more water goes through the less it absorbs the minerals and Ph/KH/GH lowers pretty much.
This is based on some testing I made.
Please tell me how does your pre-mixing work? Does it result in equal quality water or how do you control the process?

I was planning to start making water changes with this water and carefully add the minerals and make measurements in the end.
I noticed a typing error in my first message, the RO produces 150L/hour nor 150L/min.

I have a lot of filtration systems for dwell water and water parametres are good but still water isn't crystal clear but just a bit yellow. That's the only reason to try this RO system.
Sorry for bad English

So I think there's a disconnect here. You don't add any minerals to the filters, that would make the entire process of making RO/DI water irrelevant. After I run the RO/DI unit, the RO/DI water (0 GH/KH/TDS) is stored in jugs. When I need to do a water change, I add the RO/DI water to a mixing station, like a large tub or bucket, and add in the minerals/salts there for mixing and heating the water. There is no magical 6th canister with minerals in it. I repeat: you do not add minerals to any of the filters. You only add minerals after you have generated the RO/DI water, into a separate container.

If your dwell water is slightly yellow, then like Big-G said, you could link a couple carbon filters in line to increase the filtration. Are you familiar with the term "gelbstoffe/gelbstoff"? That may be the cause of the yellow tint to the water, in which case, you'd just need to run the water through a sediment filter and then a carbon filter or two in order to catch all of it; no need for the Reverse Osmosis Unit or the De-Ionization resin.

 

[TwoHedWlf]

So I think there's a disconnect here. You don't add any minerals to the filters, that would make the entire process of making RO/DI water irrelevant. After I run the RO/DI unit, the RO/DI water (0 GH/KH/TDS) is stored in jugs. When I need to do a water change, I add the RO/DI water to a mixing station, like a large tub or bucket, and add in the minerals/salts there for mixing and heating the water. There is no magical 6th canister with minerals in it. I repeat: you do not add minerals to any of the filters. You only add minerals after you have generated the RO/DI water, into a separate container.

If your dwell water is slightly yellow, then like Big-G said, you could link a couple carbon filters in line to increase the filtration. Are you familiar with the term "gelbstoffe/gelbstoff"? That may be the cause of the yellow tint to the water, in which case, you'd just need to run the water through a sediment filter and then a carbon filter or two in order to catch all of it; no need for the Reverse Osmosis Unit or the De-Ionization resin.

And if you're not already running the water through a sediment and carbon filters your RO filter isn't going to last long.

 

[Nataliia]

Thank you everybody for replies, I really appreciate it!
I was actually thinking that the re-mineralisation process couldn't be done inside a filter due to inaccuracy.
My next plan is to add inside house a about 250L tank where the RO water goes, then I add the minerals and let it stay a while, then use a small electric pump to fill in aquarium.

I got already sediment and carbon filters and also ozone generator...and yes it's propably something like gelbstoff that I'm fighting with.

I will keep you updated how my project goes on. Maybe somebody finds it useful.