RO vs Tap

[dw1305]

Hi all,

The idea that this can be the simplest of hobbies though one requiring patience (it's aquatic horticulture) gets diminished

That is the problem. I think all we can do is carry on trying to inform.

cheers Darrel

 

[Bradders]

I do think the corner is being turned. Aquarium Co-Op, Aquirum Science and this very forum are promoting the whole patience and maturity aspect. But, tankers are slow to turn .......

 

[macek.g]

Hi. A bit of background first:
I started (like many, I guess) as wanting to keep an aquarium for fish. I wasn't particularly interested in plants to start with, although I knew I didn't want plastic decorations. This was 15 years ago. Now over the years the plants have increased.

I always had trouble with algae (mainly green hair). I'm in Edinburgh so the water is very soft, it's also quite high in Phosphate. My son was dabbling in a marine reef tank so was getting RODI water from the local shop. After some very limited reading and advice, I started using RO water myself, with JBL Aquadur - and things improved greatly. For years I carried on like this and after a few tank upgrades I've still been using it. However, at the start of this year the green hair came back with a vengeance and I couldn't get it out of the Java moss and driftwood. I eventually relented and completely stripped out everything and started a fresh tank. I'm wanting to have more plants now and after finally researching online (here mainly) realise that this will be my main defence against algae. Also, I see that phosphate isn't the great evil with a planted tank.

I'm staying lo-tech and the substrate is inert. Perhaps I would have used something else if I had committed to a planted tank before redoing it. It's a Superfish Home 85 litre.

Anyway - to my question, eventually: what water should I use?

My tap water (after 4 hour degassing) is: kH:1, gH:2.5, pH:7, phos:4.8ppm, TDS:40
As an example, my tank water before my weekly 50% water change is: nitrate: 10ppm, kH:5, gH:7, pH:7.5, phos:0.05ppm, TDS:200

Is it worth considering going back to using tap water? It is very soft and lacking in TDS. Perhaps using a mix of my usual RO/Aquadur with some tap? Or perhaps even just using tap with Aquadur (or similar)?

Cheers

Welcome to our soft tap water.🙂

The only thing that is forgotten is in tap water, is NH4. In my tap it is in the range of 0.2-0.4ppm

That is why I use RO, and of course high PO4 which is standard in the UK

Sometimes I use tap water for a second tank
where the water values are:
Ca-5.64 Mg-0.95 CaCO3 -17.98 GH -1

But because I grow plants in lean fertilization RO suits me better.
You can find your exact tap water data on the Scottish water website,Water Quality Search - Scottish Water, of course they may differ slightly/significantly from what you get at the end of the chain

As for NH4 of course we can use it (many fertilizers have nitrogen in this form) but you have to bear in mind if the biology or other things are not working properly in the tank... algae may appear in the form of short hairs on the glass, decorations or plants.
Cheers

 

[X3NiTH]

The only thing you are missing in tap water is NH4. In my tap it is around 0.2-0.4ppm

Don’t worry Edinburgh gets it’s fair share of Chloramination every summer when the population nearly doubles for the Fringe, especially if it’s a hot dry summer, not so much this summer because it was a bit of a washout, I usually notice it has been dosed when the TDS rises about 10ppm above the average.

🙂

 

[Pixies]

Thanks everyone.
Going through the local water quality reports plus my phosphate measurement kit, my tap water parameters are:


I can't find the Potassium value and neither do I have a way of measuring.
So if I was to have to add anything to this at WC before considering ferts, what would it be?

If you're in an area with little to no Mg in the tap water (which is likely) - you need to add that (MgSO4 / Epsom Salt) - like 4-6 mg/l or so.

Is that the amount of MgSO4, or the target Mg+ as per above?

I’m not a fan of Aquadur there’s better and cheaper ways to remineralise water.

Same question really - what, if anything, to add to the above?

I'm guessing that the same shop that sold you the JBL Aquadur sold you these as well?

To be fair, I probably lead them - asking for a way to remineralise RO (after seeing my son add salts to RODI water for his marine tank). The shop has gone now, but was a well-known Edinburgh one.
As for the Bio CO2 stuff - I went for periods of not using it and found that plant growth did appear to improve with it. I'm using them both again now after admiring a rather impressive lo-tech display at the local Fishkeeper Scotland (Maidenhead) and speaking to staff there. I don't doubt that there is better stuff for more intensely planted tanks.

I will aim to move towards tap water and away from remineralised RO. I'll do it over several weeks, to avoid any shocks to flora and fauna. So there will be a couple more back-breaking trips to the fish shop. I won't miss that!

 

[Pixies]

Have a look at the Duckweed Index pages, I'm pointing you towards them, partially because I'm absurdly proud <"What is the “Duckweed Index” all about?"> of it, but also because it breaks down <"what is important and what isn't">.

Amazon Frogbit on order!

 

[X3NiTH]

Same question really - what, if anything, to add to the above?

If your intention is to target 7dGH and 5dKH from Edinburgh tap (3dGH 1dKH) then the easiest way I would do it would be to add 2dGH of Calcium Carbonate and 2dGH of Magnesium Carbonate, both compounds have a dKH that equals their dGH (1:1). The tank water may be a little cloudy for a couple of hours as it all goes into solution, if making up the water a day beforehand then clouding is a non problem. I would target my increased Potassium levels through fertiliser dosing (worldwide average is about 5ppm, our soft water may only contain about 1 or 2ppm). If you wanted to add the Potassium as remineralisation then I would use enough KHCO3 (Potassium Bicarbonate) to raise the water dKH by 1dKH and reduce either the CaCO3 (Calcium Carbonate) or MgCO3 (Magnesium Carbonate) by 1dGH and add back in whichever you reduced the amount of with either MgSO4 (Magnesium Sulphate) or CaSO4 (Calcium Sulphate), this way you will still be targeting 7dGh and 5dKH matching what you’ve been doing with the Aquadur. If thinking which to replace either CaCO3 or MgCO3 then I’ll make it easy by saying MgCO3 is 10x more soluble than CaCO3 so cloudy water for less time.

If all you have are soft water species of fish (Tetra etc) and no shrimp that needed extra minerals then I would use the tap water as and maybe add a little extra MgSO4 for a little extra dGH without adding extra dKH, if you need to buffer the dKH without raising the dGH any then I would be using KHCO3 (Potassium Bicarbonate).

🙂

 

[MichaelJ]

Going through the local water quality reports plus my phosphate measurement kit, my tap water parameters are:

Yes, you need Mg - 5-6 mg/l would be my recommendation with the water change - you can just front load it. If you want to keep shrimps you should add additional Calcium as well, I'd say 10 ml/l to give you 20 ppm of Ca. in total.

Now, a couple of things; Your phosphate level is pretty high. Your 4.8 ppm (mg/L) amounts to about 1.5 ppm. It's definitely workable but you may have to consider interaction with traces especially the dosing of Iron and what Iron chelate to use.

Most important; The Nickel measurement seems suspect - I think that should have been labeled ug/l (microgram/l)... Can you please double check this? 0.8 is about 10 times the tolerable EPA level. Almost 1 ppm of Nickel with possible accumulation in the substrate would make this water completely unsuitable for invertebrates and a lot of soft water fish - could you post a recent water report?

Cheers,
Michael

 

[X3NiTH]

The Nickel concentration should be expressed as ug/L, so it’s a typo, Edinburgh tapwater is treated to reduce the Fe and Mn levels (both can make water taste really bad and can stain laundry whites) so by extension there’s no possible way to have the Ni present at that level after treatment.

🙂

 

[Pixies]

If your intention is to target 7dGH and 5dKH from Edinburgh tap (3dGH 1dKH) then the easiest way I would do it would be to add 2dGH of Calcium Carbonate and 2dGH of Magnesium Carbonate, both compounds have a dKH that equals their dGH (1:1). The tank water may be a little cloudy for a couple of hours as it all goes into solution, if making up the water a day beforehand then clouding is a non problem. I would target my increased Potassium levels through fertiliser dosing (worldwide average is about 5ppm, our soft water may only contain about 1 or 2ppm). If you wanted to add the Potassium as remineralisation then I would use enough KHCO3 (Potassium Bicarbonate) to raise the water dKH by 1dKH and reduce either the CaCO3 (Calcium Carbonate) or MgCO3 (Magnesium Carbonate) by 1dGH and add back in whichever you reduced the amount of with either MgSO4 (Magnesium Sulphate) or CaSO4 (Calcium Sulphate), this way you will still be targeting 7dGh and 5dKH matching what you’ve been doing with the Aquadur. If thinking which to replace either CaCO3 or MgCO3 then I’ll make it easy by saying MgCO3 is 10x more soluble than CaCO3 so cloudy water for less time.

If all you have are soft water species of fish (Tetra etc) and no shrimp that needed extra minerals then I would use the tap water as and maybe add a little extra MgSO4 for a little extra dGH without adding extra dKH, if you need to buffer the dKH without raising the dGH any then I would be using KHCO3 (Potassium Bicarbonate).

🙂

Thanks. I'm going to go with adding as little to the water as necessary.

 

[Pixies]

Yes, you need Mg - 5-6 mg/l would be my recommendation with the water change - you can just front load it. If you want to keep shrimps you should add additional Calcium as well, I'd say 10 ml/l to give you 20 ppm of Ca. in total.

Now, a couple of things; Your phosphate level is pretty high. Your 4.8 ppm (mg/L) amounts to about 1.5 ppm. It's definitely workable but you may have to consider interaction with traces especially the dosing of Iron and what Iron chelate to use.

Most important; The Nickel measurement seems suspect - I think that should have been labeled ug/l (microgram/l)... Can you please double check this? 0.8 is about 10 times the tolerable EPA level. Almost 1 ppm of Nickel with possible accumulation in the substrate would make this water completely unsuitable for invertebrates and a lot of sensitive soft water fish - could you post a recent water report?

Cheers,
Michael

Sorry - yes it was ug/l (micrograms per litre) Typo

 

[MichaelJ]

The Nickel concentration should be expressed as ug/L, so it’s a typo, Edinburgh tapwater is treated to reduce the Fe and Mn levels (both can make water taste really bad and can stain laundry whites) so by extension there’s no possible way to have the Ni present at that level after treatment.

🙂

Sorry - yes it was ug/l (micrograms per litre) Typo

Thanks @X3NiTH and @Pixies , Thats what I thought, just wanted to make sure.

Cheers,
Michael

 

[LFNfan]

a couple more back-breaking trips to the fish shop.

Been there!

 

[Pixies]

Well then. It turns out that some of the stone in my tank is limestone/seiryu. I've had it since around 2010 when I set up my first tank. I've just tested a bit that's not being used and it fizzes under white vinegar.

So that's the Ca+ sorted then,!

If I wanted to add 5mg/l Mg+, that would be:
- assuming Epsom Salt (magnesium sulfate heptahydrate) contains approx 10% magnesium by weight.
50mg Epsom Salt per litre
or 1250mg (1.25g) per 25-litre canister of tap water.

Physics was my thing, not chemistry! Could someone wiser than me double-check, please?

Neil

 

[Maf 2500]

If I wanted to add 5mg/l Mg+, that would be:
- assuming Epsom Salt (magnesium sulfate heptahydrate) contains approx 10% magnesium by weight.
50mg Epsom Salt per litre
or 1250mg (1.25g) per 25-litre canister of tap water.

Sounds right to me.