What good is GH?

[wallo69]

One for the scientists here.

Those with the fish biology and water chemistry degrees - what does the koi we keep need out of our 'unspecified' cocktail that makes up the GH from our tap water?

I keep marine fish so I know exactly the range of Calcium and Magnesium, etc etc required to keep them healthy.

I have yet to read anywhere what the 'ideal level' that is required by our koi, and what it is.

Unless someone can provide a link to it?

Ultimately this question relates to the scenario where having taken all the rubbish out of my water, with RO filtration, I need to know what to add back, and also establish what quantities I will need to maintain these levels.

Cheers,

Mark

[Dave Collins]

There's a few of us interested Mark, one for Manky I think

Dave

[Gazza]

Hi Mark,

What is GH

I think you will find that the GH for us is not anything to worry about and its the KH we need to keep an eye on to keep the PH stable although i have never had a crash or massive drop overnight and can run close to the wind.

As in the way of do our koi get everything they need i would say that as long as you are feeding a good food then our koi should get all they need from this and i don't add anything else apart from water and food to my pond.

[Dave Collins]

Hi Gazza

What tds are you running in your pond and do you top up with RO only or a mix of RO and tap water (to add the vital missing elements )

Dave

[Gazza]

Hi Dave,

Not a good one for me at the moment as Ive been playing and cocked my pump up so the TDS is on the up

I normally run the pond at PH around 7 and TDS around 100 and do run some supply water sometimes (very rare as i can forget to turn it off sometimes and end up with hard water again) but normally use Bi carb.

[kimr]

This is a good question for those still struggling with the chemistry and science of water, I would love to an RO unit but do not feel qualified enough to do this as yet, so having questions like this help. I had a call to add bi-carb as I had moved to a very soft water area with hardly any GH or KH all I know after adding it I had the most horrendous blanket weed I had ever seen, not sure if it was linked but a bit wary of adding it again.

[Geoff9]

Hi Dave
If I have understood it correctly the good bacteria needs the KH to suvive not the koi,thats what a filter crash is all about no KH the good bugs die.

Regards Geoff

[finkoi]

Hi Gazza

You say that the fish get everything they need from the food we feed. I agree but what happens when they stop feeding for some reason?

Also very interested to find out if we need to add anything extra to the water?

Andy

[greg]

Hey Mark,

I'm no scientist as you know - but I will offer an opinion. Sadly it falls back to the last thread on here we talked on. PH swings - It's all linked and cannot be any other way.

I still think your trying to be too detailed in what is in your water. I am firmly in the RO is a plus for my pond camp, and I will continue to run it. But to analyse it too deeply will simply send me round the bend so I settle for running the readings I want by using the good old fashioned "mix method" of trickling both RO and normal purified tap water.

We all began tinkering with RO at similar times and have all ventured down differing routes which is interesting. To me though this comes back to I took the advice of Mike Snaden (amongst others) when I started and Mike has seen me right all the way through my RO koi keeping time. He still uses the same methods (albeit slightly differing equipment) that I am, and to my mind that's good enough for me.

My instinct is that if your worried that the koi will not get everything they need from the food they get / they stop eating etc - then the only solution is to add "mix" water to ensure they get a "trace" of everything. I certainly don't think any of us are keeping koi of a level that its so critical that we control every single element that makes up our water because we might notice a few mm less growth or a slight issue in the beni on one Kohaku.

[kimr]

Hi

I was going to post on water as very soon I will be on the move back up north, the readings I had up there before were PH 6.4 GH 2 KH 2-3. When the Koi first came up there I thought I would have really bad issues with them jumping out of the pond and not doing to well in general, as they were coming from an area of PH being 8.0 I was concerned about the GH and KH as the PH was so low so I tried the Bi-Carb then went down the route of Lithaqua in the biological filter this must of kept things stable, but after saying all of this the Koi were doing great and the growth and skin appetite everything was brilliant. So my question is as KH seems to be the one to really keep an eye on what is the best KH to have and with a PH of around 6.4 and KH of 2-3 would there be any need to run an RO. My understanding on RO is to reduce the PH and take the rubbish in the water. The water up there is so soft there is limescale at. Also can anyone please ppoint me the right dirrection to something on water that I can understand.

Many thasnks for any replies and I am sorry if I have asked to many questions

[wallo69]

Hey Mark,

I'm no scientist as you know - but I will offer an opinion. Sadly it falls back to the last thread on here we talked on. PH swings - It's all linked and cannot be any other way.

I still think your trying to be too detailed in what is in your water. I am firmly in the RO is a plus for my pond camp, and I will continue to run it. But to analyse it too deeply will simply send me round the bend so I settle for running the readings I want by using the good old fashioned "mix method" of trickling both RO and normal purified tap water.

We all began tinkering with RO at similar times and have all ventured down differing routes which is interesting. To me though this comes back to I took the advice of Mike Snaden (amongst others) when I started and Mike has seen me right all the way through my RO koi keeping time. He still uses the same methods (albeit slightly differing equipment) that I am, and to my mind that's good enough for me.

My instinct is that if your worried that the koi will not get everything they need from the food they get / they stop eating etc - then the only solution is to add "mix" water to ensure they get a "trace" of everything. I certainly don't think any of us are keeping koi of a level that its so critical that we control every single element that makes up our water because we might notice a few mm less growth or a slight issue in the beni on one Kohaku.

Hi Greg,

Yes, we have all seemed to verture onto different path's on this RO journey YOU started us on! lol

But dont confuse my question with 'worry' as at present I have had the least eventful year (so far, and touch wood) with all my koi eating well, and I would guess (to be revealed when bowling for Cambridge) growing well, so all is 'OK' in Saxilby.

That doesnt mean this question is moot, or 'to detailed' its is simply a question that to date seems un-answered, and forms part of the whole equation about how best to keep our koi.

When we know exactly what marine, brackish etc fish require, and with one expert saying carp require hard water (genetically) and the current expert saying not (you know I am with the latter approach, or why am I using RO?) so it is not unreasonable for this question to be answered in full rather than take the 'easy option'.

We are travelling different paths, and thats fine, for the reasons already stated, however my need for answers wont let it rest there, especially when with running an RO recycling plant (ultimately) it may mean you remove even more from the pond than a steady trickle of RO will.

We have a reliance on the 'hobbyist anecdote' in this hobby, and I am sure in the most part this will never change, but lets see if the scientists can put some effort in and explain this one eh?

Mark

[wallo69]

the Koi were doing great and the growth and skin appetite everything was brilliant

Kim,

Noting my comment on 'hobbyist anecdotes' I feel it wrong to offer an 'opinion' but the highlighted bits of your post suggest to me you have very good water, and whilst may need to keep an eye on the ph, and keep replacing water, dont need to do much else!

I wish I had your readings!

I would however suggest you visit the Yume Koi web site and visit the Articles section for that particular dealers take on water..... interesting reading!

Mark

[Dave Collins]

As Mark says, we are just trying to better understand Koi and water keeping, there is no obsession here.

Duncan once said that in order to prevent pH crashes then KH must always be higher than GH and as we all know KH is used up by the biological filter. GH can even be as low as zero but we must find a way of keeping the KH at a level of at least 1dH.

As some of you will have seen I’m following Andy’s (finkoi) recycling method. I’m a few months behind Andy in this and easing into it slowly. I fully expect that I will need to add a very small amount of tap water on a daily basis and maybe some clay but without some sort of scientific input I’m just shooting in the dark.

So, does anybody out there have a clue?

Dave

[wallo69]

Hi Dave,

Just about to order the 400gpd membranes, and depending on the genius of Mr Finch to get working, but hope to be catching up soon myself!

Keep up the good work!

Mark

[Duncan]

Just my opinion


I have tried or opted to stay out of this, as I fear no definitive conclusion can be reached.

You see water is what it is! Just because certain properties are present it does not follow that they are needed. Air is the name given to atmosphere used in breathing, Dry air contains roughly (by volume) 78% nitrogen, 20% oxygen, 1.0% argon, 0.04% carbon dioxide, and small amounts of other gases and water But we make use of just the oxygen element, the presence of the other gasses just serve to crowd out/dilute the oxygen to prevent oxygen toxicity in the body, indeed the body does not absorb atmospheric nitrogen unless its pressurized.
All this serves to point out that just because an element is there it does not automatically follow that it’s used or needed to any great degree.

Water is the great universal solvent be it sea or fresh water. Given conditions and enough time water will dissolve and absorb just about everything in varying amounts and densities, hence its rich and diverse make up, it does not follow that’s it’s all needed. So waters chemical and mineral make up will vary and this will largely depend on environmental and regional factors, for instance, wales is known for having very low TDS and very soft acidic water while other parts of the country endure hard unyielding water types these are regional and environmental influences on water and mineral content that will vary greatly yet given these wide and varied differences the carp species adapts and occupies a niche in both dramatic variations of water. So clearly if the carp does need minerals it cannot be much

Mention has been made of marine fish’s chemical/.mineral requirements, while there is some research into trace elemental requirement of sea fishes, I’m willing to bet a lot is based on the chemical makeup and high mineral and elemental content of sea water ( it exists therefore it must be used). To attempt to draw a comparison between salt and fresh water fishes based on the makeup of the different water make up would be a mistake, as the metabolism for both types of telehost fish are very different, for instance sea fish must drink where as fresh water fish don’t. There is a huge list of trace elements in sea water yet only a handful are used as supplemental and most of these are for corals. Marine guys use calcium reactors yet this is for the purpose of corals so where do marine fish get mineral from? I believe diet.


So we come to the nub of the matter

As many of you know I started running RO water about the same time as Mike Snaden did and for most of those years I ran a tds of around 70-100ppm consisting of some KH but absolutely zero GH.
Now here’s the thinking that convinced me GH in water form was not required


Everyday pond water is made up of KH and GH and odd elements that’s occupy neither niche, everyone knows that KH will vary on a weekly basis in a downward trend, as pond by design consumes KH. So if you start say with a KH of 5 in a few days/weeks that will be 4 then 3 and so on.

Here’s the thing if you ran a pond with a GH of 4 without refreshing or adding to the pond in 12 months you would still have a GH of 4, very little if any is used.

So I drew solace from the fact there were environmental situations regionally where GH was virtually nonexistent and in the pond scenario very little was used anyway and also, carp were largely kept in japan in very poor ( mineral wise) very low pH land locked situations. So you then ask yourself the question if indeed they do need mineral where does it come from?

The answer to me was diet if you think about it logically if a fish needs minerals it must therefore absorb these minerals. we feed koi whole fish ground and concentrated in so doing we are feeding them all the minerals and trace they need having being absorbed by the food fish in the first place up to and including hydrocarbons and PCB’s but that’s another story

So with one or two food exceptions where no animal based protein is used I believe diet will provide all the mineral content they require as they are what they eat. In fact I would go so far as to say worry not about GH so much but worry more about things that are being fed to koi that are totally alien to carp such as, soya, silkworm, chicken & beef derived protein etc.