Magnesium in tap water

tiger15

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You have chalk formation in England, which is calcite with no Mg. So dosing epsom to supplement Mg makes sense. Do your garden shops sell crushed dolomite from import. Washing the dust out and keep the large grains should work. Decorative marble chips from garden shops is the next closest thing to dolomite.
 

dw1305

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Hi all,
Do your garden shops sell crushed dolomite from import.
Possibly.

I don't know where we import our dolomitic limestone from, might be Italy, Turkey or even the USA. I've only ever seen it as a fine pink powder.

There are three or four dolomitic limestone quarries still open in the UK, but I assume just as local aggregate quarries.

cheers Darrel
 

dw1305

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Hi all,
Yes TDS out the tap is consistently about 310
OK, that is quite interesting. I was expecting the TDS reading to be lower than that. A reading of 310ppm TDS is about 485 microS conductivity.

This means that there are some other ions (unspecified) in the water. It might be sulphate (SO4--) or chloride (Cl-).

We know quite a lot about the water in Burton on Trent from its use in brewing, this is from <"All about Beer">
Burton water also has the highest calcium content of any major brewing region, the highest magnesium, and low levels of sodium and bicarbonate.
So I would assume that your water shows some similarity with this, and that also accounts for the lack of lime-scale.

cheers Darrel
 

jameson_uk

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Hi all, OK, that is quite interesting. I was expecting the TDS reading to be lower than that. A reading of 310ppm TDS is about 485 microS conductivity.

This means that there are some other ions (unspecified) in the water. It might be sulphate (SO4--) or chloride (Cl-).

We know quite a lot about the water in Burton on Trent from its use in brewing, this is from <"All about Beer">So I would assume that your water shows some similarity with this, and that also accounts for the lack of lime-scale.

cheers Darrel
Burton is 15/20 miles north of here and I kind of assumed it would be different as it is sat in the Trent Valley.

[OT]
The brewing stuff is partly historic but there is an actual process called Burtonisation (https://en.m.wikipedia.org/wiki/Brewing_methods#Burtonisation) which is effectively making the water like they had in Burton. My understanding is that these sources became unfit for brewing a long time ago and even Carling (if you call it beer ) burtonises tap water as part of the brewing process, which must mean the tap water is different to these old sources.
[/OT]

Would this composition of water potentially cause me issues? Other then the shrimp molting I have always had issues growing Java Fern, Rotala and Bacopa which are apparently easy to grow.... The java Fern just exists and never seems to really grow and the stems just tend to look a bit unhealthy but never show any obvious nutrient deficiency. I did try lots of different combinations of light and flow without success so ended up giving up on them. The crypts, limnophilia sessiflora and Hyrophila siamensis all seem pretty rampant.

Is there anything I ought to look in terms of tweaking ferts (I dose http://www.theplantedtank.co.uk/allinone.htm weekly)
 

jaypeecee

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Problems with plant uptake often occur because of the calcium: magnesium ratio. Basically it is just a numbers game, if you have a very high calcium to magnesium ratio, the ion crossing the cell wall into the plant is almost always a Ca++ ion, not an Mg++ one.
Hi Darrel,

Thanks for that.

Ca++:Mg++ ratio in my tap water is 121.16 mg/l:4.45 mg/l (mean values) = 27:1. That's pretty high, I guess. What would be the visible effects of this on the plants?

JPC
 

dw1305

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Hi all,
Burton is 15/20 miles north of here and I kind of assumed it would be different as it is sat in the Trent Valley.
I don't know enough about the Geology to really say, I think there might be enough evaporite minerals (like Gypsum) in the whole area to effect the water. Droitwich has salt deposits and Barr Beacon ridge etc are Triassic age sandstones laid down in a desert.
Ca++:Mg++ ratio in my tap water is 121.16 mg/l:4.45 mg/l (mean values) = 27:1. That's pretty high, I guess. What would be the visible effects of this on the plants?
Yes, it is quite high, but pretty standard for most of the hard water in the S. UK. Any plants that are naturally adapted to hard water probably won't show any signs of deficiency. Have a look at @Akwascape's <"Cryptocoryne parva carpet"> thread for some suggestions.

Plants that are naturally form softer water may show signs of magnesium (Mg)/and or iron (Fe) deficiency. Both deficiencies cause chlorosis (see Bucephalandra below), if it is in older leaves then magnesium deficiency is likely, if it is in new leaves iron is a more probable cause..

magnesiummangel.jpg
Would this composition of water potentially cause me issues? Other then the shrimp molting I have always had issues growing Java Fern, Rotala and Bacopa which are apparently easy to grow.... The java Fern just exists and never seems to really grow and the stems just tend to look a bit unhealthy but never show any obvious nutrient deficiency.
Unfortunately I don't know.

Does <"your Amazon Frogbit"> still look healthy?

cheers Darrel
 

jameson_uk

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Does <"your Amazon Frogbit"> still look healthy?

cheers Darrel
On the whole yes.. This is from Betta tank which is within reach but the same in main tank plus other poor leaves but I am not sure how much of that is down to humidity and mechanical damage. I have kind of resigned myself to weekly pruning of leaves. I removed all leaves like this at the weekend so these leaves are since then.
d12c40e2073d31f45c789d43065448d5.jpg
7fb79c87f5ed55da8539acabed4735c1.jpg
781f17d3099613f2a70c3d831ea8c3a6.jpg
 

dw1305

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Hi all,
On the whole yes.
Not too bad at all, so nothing major.
I removed all leaves like this at the weekend so these leaves are since then.
The only thing I'd say is they look a bit paler than they would for optimal growth and the older leaves are definitely senscing more quickly than you would expect.

I might try a little bit more potassium nitrate (KNO3) and Epsom Salts (MgSO4.7H2O), it doesn't need to be very much of each. If you are sub-optimal in K+ NO3- or Mg++ that should give you fairly rapid greening.

cheers Darrel
 

dw1305

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Hi all,
I might try a little bit more potassium nitrate (KNO3) and Epsom Salts (MgSO4.7H2O), it doesn't need to be very much of each. If you are sub-optimal in K+ NO3- or Mg++ that should give you fairly rapid greening
Hi @jameson_uk as we have a few threads on <"nutrient availability in harder water ">, and you have another <"Frogbit thread">, can I ask whether you added the Epsom Salts etc? and if you did? what happened?

cheers Darrel
 

jameson_uk

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Hi all,Hi @jameson_uk as we have a few threads on <"nutrient availability in harder water ">, and you have another <"Frogbit thread">, can I ask whether you added the Epsom Salts etc? and if you did? what happened?

cheers Darrel
I add Epsom Salts as part of my all in one solution anyway. I think we figured out my water is abnormally high in mg for UK.

I ended up putting loads of ferts in when the frogbit started to turn but it didn't really seem to make a lot of difference. I got hold of some EDDHA mix from @Zeus. And have been adding that which does seem to have made things a bit greener but I was still seeing issues with the frogbit (odd shaped leaves, the lace effect, what appeared to be leaves melting etc.)

I think there are / were a number of issues so in order to work out what is going on I have removed all the frogbit and only put back healthy plants topped up with some from my Betta and shrimp tanks. This has reduced the number of plants by about 60% (I think some of the issues were down to overcrowding). I have also adjusted the spray bar a little as I think this had crept higher and higher over time and was causing a bit more surface agitation and also drops splashing onto the plants.

I am going to monitor things now as I know everything was healthy looking a couple of weeks ago.
 

jameson_uk

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A few pics. This is the main tank which looks on the whole pretty healthy
d1461f9e59c8f415137946e3a31f44d7.jpg


There are however a couple of plants not looking great
8cc56f04a844fb1c46829f81632b7766.jpg
e6d610b1df0ae04d4506fe6fb97bbbae.jpg
fc78c25c438c5f3ed343a467e3511a43.jpg


I do wonder whether some of this is snail related...

Interestingly the plans either seem fine or poor. The poor ones also seem to be sending off plantlets (sometimes two it three which I haven't seen before)
 
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Sorry to hijack the thread but I have been reading about the calcium,magnesium ratio and all info points towards a 4:1 - 3:1 calcium - magnesium ratio. Other source's say it doesn't matter about ratios? I have hard as nails water @Zeus. We share the lovely Yorkshire water. My calcium is 121.5mg/l and magnesium 8mg/l. According to James planted tank calculator using magnesium sulphate I'd need to add 8 tea spoons magnesium on water change day to achieve the 3:1 ratio it just seems excessive?
My maths is poor I won't lie,
So 121.5 / 3 = 40 ( there abouts )
- 8ppm magnesium already in tap water = 32ppm to make up to the 3:1 ratio?
 

Sammy Islam

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I've always wondered about these ratios too, as theres a lot of contradictory statements floating about the net regarding the ratio between k/mg/ca.

Do i think ratios matter? I'm not sure, but having 100+ppm of ca compared to other nutrients surely can effect the uptake of things? I dose full EI, apart from full mg at 10ppm, i dose about 2tsp in my AS900 which should give me about 6ppm when doing a water change.

In my experience, so far things are going very well on my new scape and i can't really see any deficiencies yet as i'm only a month in so far.

In my old tank if i dosed too much mg, 10+ppm some of my hygrophila polysperma leaves began to curl, maybe this had something to do with the ratio between mg & k, i don't know.

Also what about people (like me) who use hard water, have seiryu stone and do daily top ups with tap water? They are increasing the CA, which is already high, on a daily basis compared to the other nutrients. How does this effect things? If high CA interferes with the uptake of other nutrients, is the answer to dose a little bit more of everything? Even if we already dose EI...

Here is a thread i started a while ago:
https://www.ukaps.org/forum/threads/100-ppm-calcium-and-nutrient-uptake.59115/
 

dw1305

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Hi all,
A few pics. This is the main tank which looks on the whole pretty healthy
d1461f9e59c8f415137946e3a31f44d7.jpg


There are however a couple of plants not looking great
8cc56f04a844fb1c46829f81632b7766.jpg
e6d610b1df0ae04d4506fe6fb97bbbae.jpg
fc78c25c438c5f3ed343a467e3511a43.jpg


I do wonder whether some of this is snail related...

Interestingly the plans either seem fine or poor. The poor ones also seem to be sending off plantlets (sometimes two it three which I haven't seen before)
That looks like iron issues.

Cheers Darrel
 

jaypeecee

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I have hard as nails water @Zeus. We share the lovely Yorkshire water. My calcium is 121.5mg/l and magnesium 8mg/l.
Hi @Craig Matthews

Your comment above caught my attention. When I used to live in West Yorkshire, I considered the tap water to be soft. Could easily get a nice lather when washing my hands with soap. By comparison, I now live in Berkshire where I consider the tap water to be hard. But, here's the interesting bit - the mean calcium content of my tap water in 2018, for example, was 121.16 mg/l and magnesium was 4.45 mg/l. So, something doesn't stack up. Your calcium content and mine are almost identical! Or, maybe I'm overlooking something?

JPC
 

jaypeecee

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Hi Folks,

Quite why my reply to @Craig Matthews above got embedded in the way that it has, I'm not sure. No doubt my mistake. Sorry for the confusion! Yet another 'senior moment' on my part.

JPC
 
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Well its the first week of trying the 4:1 ratio so I shall let you know how it goes. I've had to add extra K2SO4 as my hygrohila Compacta is showing sighns of defiency and I don't want to add k in the form of kNO3 as I have enough nitrate ( 20ppm per week). I will report back and let you know how it goes.
 

Zeus.

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High levels of calcium (Ca) can interfere with the uptake of both iron (Fe) and magnesium (Mg). Hard water is likely to have <"some magnesium"> in it (my guess would be that <"1 - 5 ppm" is fairly typical>),
@dw1305 So for folks like myself living in the NE should we be adding up the Mg. in our tap water?

My water company reports an average of 5mg/L Mg. So after a 50% WC that would add 2.5ppm Mg so therefore is all this Mg. available to plants ? If so should we therefore adjust our dosing of MgSO4.7H2O to reach our target Mg ppm

e.g. So after a 50% WC in 500L tank we have added 2.5ppm Mg. Then if we add 5 teaspoons of Epsom salts(MgSO4.7H2O) to tank which yields 5ppm Mg. In a 500L tank we have 7.5ppm Mg. with the WC and the salts added
 

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