BUYING FIRST RO FILTER HELP.

[dino21]

Think we would get a simple GH /KH test kit and establish whats in the water coming through your tap; then dependent on what folk suggest is a good hardness level for the stock you intend to keep, will determine the best way to prepare your water.

Not a product we have used but this good supplier stock this brand -
JBL Aquadur

 

[mugsy]

Ok thats what il do. Il get some tests done and see what numbers are. Thanks

 

[_Maq_]

Commercial reminalizers feature serious drawbacks. Mainly because they prefer instantaneous solubility over optimal composition. Beside that, they are usually scandalously over-priced.

 

[mugsy]

So Maq do u think mixing some tap water with the ro is good enough?. Iv ordered a test kit,when it arrives il test my water and put up results to see what you think.

 

[ian_m]

I believe tap water ought to be low in ammonia. And chlorine gets removed in activated carbon pre-filter.

The ammonia in the water is from breakdown of chloramine into ammonia and chlorine and these not being absorbed by the carbon filter due to filter media exhaustion or water flow rate too high.

 

[ian_m]

Other thing to consider is a booster pump, as most RO systems are rated at 8 bar inlet pressure and 25'C water. If your mains water pressure is considerably lower than 8bar then your RO flow rate will be considerably less than the quoted flow rate.

Also some water boards/authorities require notification of fitting of an RO unit to their supply, especially if using a booster pump, though in practice I think all they require is that you have fitted a double check valve to they incoming supply to prevent you accidentally pumping water into their supply pipes.

 

[dw1305]

Hi all,

i will attach links to my local water report

We need a postcode or approximate location to get the active page. This was for a random Coleraine postcode.

Commercial reminalizers feature serious drawbacks. Mainly because they prefer instantaneous solubility over optimal composition. Beside that, they are usually scandalously over-priced.

I agree with @_Maq_ , commercial remineralizers <"are just a rip-off">.

Have a look at <"James' Planted Tank - Re-mineralising RO Water">

You can buy potassium bicarbonate (KHCO3), calcium chloride (CaCl2.2H2O) and magnesium sulphate (MgSO4.7H20) cheaply from ebay (they all have <"food / health usages">). There is also <"Oyster / Cockle shell chick grit">.

So Maq do u think mixing some tap water with the ro is good enough?.

It really depends how hard you tap water is. I use tap water as a remineraliser, but it is reliably <"from a deep limestone aquifer"> and 17 : 17 dGH : dKH.

Have a look at <"Some handy facts about water">.

cheers Darrel

 

[_Maq_]

The ammonia in the water is from breakdown of chloramine into ammonia and chlorine and these not being absorbed by the carbon filter due to filter media exhaustion or water flow rate too high.

Chloramine is no longer in use for tap water in my country. Is it different in the UK?
As for chlorine, I live under impression that AC acts as a catalyst, so it never gets exhausted in this respect. Am I wrong?

 

[dw1305]

Hi all,

Chloramine is no longer in use for tap water in my country. Is it different in the UK?

Unfortunately it is, and chloramine is actually used much more widely than it was. There are two major scenarios:

• Emergency dosing, due to the breach in the <"integrity of a water main">, and
• Routine dosing where the end of water supply line is <"some distance from the treatment works">.

A lot of the chloramine use relates to the <"business model of our water companies"> and <"lack of effective regulation">.

cheers Darrel

 

[dino21]

Hi all,

Unfortunately it is, and chloramine is actually used much more widely than it was. There are two major scenarios:

• Emergency dosing, due to the breach in the <"integrity of a water main">, and
• Routine dosing where the end of water supply line is <"some distance from the treatment works">.

As a tap water only user, it does seem to make us question how effective the typical Dechlorinators are ?
We currently use Seachem Prime at its standard recommendation, but its instructions do say that -
For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to 5 times normal dose may be used. If temperature is > 30 °C (86 °F) and chlorine or ammonia levels are low, use a half dose.
Though how can the typical aquarist know how much Chlorine or Chloramine is in the tap water ? Should we be testing the water for nitrite before use . Should we always double or 5x dose just to be sure ?
Normally we draw the water, add the Declorinator, start a small circ pump and allow at least 12 hours before using it.

 

[dw1305]

Hi all,

As a tap water only user, it does seem to make us question how effective the typical Dechlorinators are ?

Really <"open to question">

Though how can the typical aquarist know how much Chlorine or Chloramine is in the tap water ?

You can taste chlorine at above ~0.5 ppm. That doesn't <"particularly help with chloramine">, but you can use <"the normal methods"> for getting rid of ammonia (TAN) and the trickle of chlorine gas should outgas fairly quickly.

...... The average person can smell/taste free chlorine (Cl2, HOCl, OCl- – at 0.5 – 1 mg/L) more so than monochloramine (NH2Cl – at 3 mg/L).

Should we be testing the water for nitrite before use . Should we always double or 5x dose just to be sure ?

No and no. I'm <"not a tap water user">, but if I was I'd use small volume water changes, that way it doesn't matter which disinfectant is in your tap water, as long as you keep heavily planted tanks..

Normally we draw the water, add the Declorinator, start a small circ pump and allow at least 12 hours before using it.

I think that is pretty sensible if you are doing larger volume water changes. I'm guessing that most of the problems with chloramine (or emergency chlorine dosing) are when you carry out a <"large volume water change"> using tap water and a mixer tap etc.

It is fairly grizzly reading, but have a look at Shane Linder's tale of woe about the Washington DC water supply in, <"Expert, maybe not....">.

cheers Darrel

 

[dino21]

If the water company decide to use chloramine in your water and your pre-filter is not a de-chlor type, or exhausted or flowing to fast then then you can end up with ammonia in your RO water (also given away by increased tds/conductivity).

Learning here -
Seems our local water board used Chloramine, see below.
There are a lot of 10" RO cansiter type Activated Catalytic Carbon filters out there like Yvair, Matrikx CTO etc with a wide price ranges - any recommended brands for the smaller fish / planted tank use ?

 

[mugsy]

Folks i have received my test kit and ro system. So im going to test my tap water to see what you folks think and if safe to mix with ro water and how much approx.. what tests do u need to know for tap water?
Thank you
Sean

 

[dino21]

Folks i have received my test kit and ro system. So im going to test my tap water to see what you folks think and if safe to mix with ro water and how much approx.. what tests do u need to know for tap water?
Thank you
Sean

If you have a TDS meter, then a reading from that gives a general guide followed by GH and KH from your liquid test kits.
Don't forget you can tee off from your RO system just before the Membrane to provide your tap water which will have been cleaned up a bit by the pre and carbon filters, but the hardness will not have been affected.

Re our last post comment / enquiry, you might want to look the point made by @ian_m and fit a Catalytic Carbon filter in place of the standard Carbon block one.

 

[mugsy]

If you have a TDS meter, then a reading from that gives a general guide followed by GH and KH from your liquid test kits.
Don't forget you can tee off from your RO system just before the Membrane to provide your tap water which will have been cleaned up a bit by the pre and carbon filters, but the hardness will not have been affected.

Re our last post comment / enquiry, you might want to look the point made by @ian_m and fit a Catalytic Carbon filter in place of the standard Carbon

 

[mugsy]

Ok folks. Bit of a blunder. I ordered a freshwater master test kit thinking it would have everything but i doesnt have GH or KH🥺 my fault for assuming.
I did test tds and my tap water comes out at 185ppm tds.
Do i need to now buy the Gh and Kh to get those results or does the tds give you an approximate idea? Thanks

 

[dw1305]

Hi all,

I did test tds and my tap water comes out at 185ppm tds.
Do i need to now buy the Gh and Kh to get those results or does the tds give you an approximate idea? Thanks

You can and you can't, but there is a bit of "unpacking" to do.

The TDS (ppm Total Dissolved Solids) meter doesn't measure TDS, it makes an estimation from the conductivity reading (in microS) and a conversion factor, have a look at <"Guide to TDS">.

Conductivity meters are pretty good, you just need to find what the <"conversion factor"> is (either 0.64 or 0.5), so 100 microS is 64 (or 50) ppm TDS. If you can set the meter to read "conductivity in microS"? I would.

The "you can" bit is based on the assumption that the majority of ions in solution will be calcium (Ca++) and bicarbonate ions (2HCO3-) from dissolved limestone. In most cases this is a fair assumption, but it is an assumption.

This is the bit where probability comes into play, after making certain assumptions.

• @Nick potts is right there is no inherent link between conductivity, dGH or dKH and no link between dGH and dKH either, but in most freshwater all three values are linked because <"they are all relate to the amount of dissolved limestone"> (CaCO3) in the water. <"In Torbay"> (where Nick resides) you can be 99.9% sure that the link for all three parameters is true.
• Calcium carbonate <"isn't soluble in water">, but it is <"soluble in weak acids">, and rainwater is a weak acid because of the amount of dissolved CO2 it contains. At 400ppm CO2, the solubility of CaCO3 (in pure H2O), means that water from a limestone aquifer has about 18 dGH and 18 dKH. The derivation of both <"GH" and "KH" is a bit strange"> but fully described in <"Larry Frank's "the Krib" article">.

Can you get figures <"from your water company">? They have an analytical lab. and those values should be accurate.

I ordered a freshwater master test kit

Personally I don't like making decisions <"based on test kit results">. This isn't because I don't think that water parameters are important, they are and I do, but because the <"test kits available to us"> are often not accurate enough.

Have a look at <"New bit of kit - MP-AES">

cheers Darrel

 

[mugsy]

Thanks very much Darrel and all the guys for helping me get off to the best start i can. Iv attached my local water report for my post code. See what you think.

 

[_Maq_]

Your water is "normal". Surely you can have a nice tank with that. However, if you aim to reach higher levels in plant-keeping, reverse osmosis (or a reliable source of clean rainwater) is obviously the way to go. Also, most tropical fishes prefer soft & acidic water.

 

[dw1305]

Hi all,

Iv attached my local water report for my post code

Perfect. You can use <"Hardness convertor"> to check the different units, but the one we are interested in is <"degree German (dGH)">. There is a worked example here <"How Do I Work Out K/Mg/Ca in Tap Water?">.

This is the definition of dGH

........ By definition, 1dGH = 10 mg/litre CaO
Atomic Weight Ca = 40, O = 16, CaO = 56
So 10 mg/liter CaO contains 40/56 *10 = 7.143 mg/liter of Ca
By definition ppm Ca is not for elemental calcium but for ppm CaCO3.
Atomic weight CaCO3 = 100
So 7.143 mg/liter of elemental Ca would be expressed as 100/40 * 7.143 = 17.8575 mg/liter(ppm)CaCO3.
1dGH = 17.86 ppm CaCO3 and 7.143 ppm Ca ............

I agree with @_Maq_

Your water is "normal". Surely you can have a nice tank with that.

Personally I'd use <"your tap water as a remineraliser"> and just aim for a <"conductivity datum"> value / range.

..... I don't add a set amount of tap water, I just aim to remain in the <"conductivity datum range">. I'll be honest I don't very often even use the conductivity meter, I usually just go on the <"state of the snail shells">. I'm going to say that somewhere around 3 - 4 dKH (and dGH) is pretty good for most fish and plants.......

Also, RODI water is now just RO water coming out at 6ppm TDS all the way down from 490ppm. Pointless running DI section to knock it down to 0ppm if you’re going to remineralise with the source tap water.

In tank TDS is now roughly 120ppm. Not particularly interested in complicating things further than this. Tap water here is pretty comprehensive and has some of everything.

Tap report puts 10% tap mix into RO at Ca 11.1pm and Mg 0.83ppm. Supplementing Mg with a very accurate ‘dash’ of magnesium sulphate 😂 Can already hear those who love their expensive and relatively accurate scales screaming at this blasphemy but… meh

cheers Darrel