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Hardness & algae

idris

Member
Joined
3 Jan 2011
Messages
816
Location
Herts
Ovwr the last few months I've had a lot more algae than I used to get.
I know there are various factors I can look at but I'm trying to consider what has changed.
A significant difference is that I've moved from tap water to rain water.

Our tap water is off-the-test-chart hard. Literally. GH>180 and KH >240 with a pH around 7.2
Our rain water is GH<40 and KH<30 with a pH of 6.3

Is the change likely to contribute to algae growth?
 
Hi all,
Ovwr the last few months I've had a lot more algae than I used to get. I know there are various factors I can look at but I'm trying to consider what has changed. A significant difference is that I've moved from tap water to rain water.....Is the change likely to contribute to algae growth?
The only thing I can think of is that it might be nutrient availability. The change would mean that ions like iron (Fe++(+)) and phosphate (PO4---) are more available in softer water.

Before you changed to rain water one of these ions was <"Liebig's limiting nutrient"> because that ion was going out of solution as <"an insoluble compound">. After the change this isn't happening. There is a bit more discussion in <"From Reef to Nature...">.

I might try upping the plant mass and see what happens.

cheers Darrel
 
I've very hard tap water too with a pH of 7.7 due to my area being karst limestone.
I seem to have magnesium deficiencys in my plants despite dosing micronutrient fertiliser.
I wonder could the magnesium deficiency really be an iron deficiency due to the water hardness.
I might invest in an RO filter or possibly try lowering ph another way.
 
Actually I will be starting to add co2 next week once my new lighting arrives. I'm expecting that it will lower the pH quite a bit.
Would that lower pHincrease the availability of Mg and Fe ions?
 
Hi all,
Welcome to UKAPS.
my area being karst limestone.
Are you in the Burren?
I might invest in an RO filter or possibly try lowering ph another way.
I'd really strongly suggest rain water, unless you are very close to the Atlantic? And even then you would only need to discard the water after there had been a big storm, with a lot of salt spray. Do you have a conductivity (TDS) meter?
I seem to have magnesium deficiencys in my plants despite dosing micronutrient fertiliser.
I wonder could the magnesium deficiency really be an iron deficiency due to the water hardness.
Yes, you could have magnesium (Mg), deficiency mainly because the <"carboniferous limestone"> is fairly pure and doesn't contain <"much magnesium"> for <"geological reasons">.

Iron (Fe) is a bit different, it needs to be chelated to keep it plant available in harder water, and <"some chelators are better than others"> as the pH rises.
Would that lower pHincrease the availability of Mg and Fe ions?
It may, if the pH goes below pH7, but even then insoluble compounds will be formed during the CO2 off time period.

cheers Darrel
 
Ah thanks Darrel,
I'm in Galway near edge of the Burren about 6 miles inland. There are sheets of limestone under the lawn in my back garden but my water comes from a large lake to the north (lough corrib) that sits on limestone pavement.
My father used to run a few mass spectrometers in a Uni before he retired (triton icp etc)
He did run a few tests on the water but I don't remember anything much other than calcium in the results.
Rain water would be easy to collect here for most of the year, I'll try making a DIY collector during the winter so.
I'll have to get a tds pen so to help out while I figure out how to manage my water.
I remember from A level chemistry that H+ ions from a strong acid were good to help make most metals more available but I don't think I'll get below ph7 unless I use 75% plus rainwater.
Cheers,
John
 
Ovwr the last few months I've had a lot more algae than I used to get.
I know there are various factors I can look at but I'm trying to consider what has changed.
A significant difference is that I've moved from tap water to rain water.

Our tap water is off-the-test-chart hard. Literally. GH>180 and KH >240 with a pH around 7.2
Our rain water is GH<40 and KH<30 with a pH of 6.3

Is the change likely to contribute to algae growth?
Water hardness has nothing to do with algae.
It is correct that there are many factors. Hardness is not one that warrants attention.
I seem to have magnesium deficiencys in my plants despite dosing micronutrient fertiliser.
On what basis have you concluded that the tank suffers Mg or Fe shortage?
It's better to list the symptoms rather than to conclude a cause.

Cheers,
 
Thanks all.
I thought it was unlikely, but was just trying to thnink through all possibilities.
 
Actually I will be starting to add co2 next week once my new lighting arrives. I'm expecting that it will lower the pH quite a bit.
Would that lower pHincrease the availability of Mg and Fe ions?
you have mentioned that your tapwater pH is 7.7 but that doesn't necessarily mean that the pH in your tank is 7.7. Some aquasoils do buffer the pH quite a bit.

My low tech tank without CO2 injection is pH 6.7, but my tapwater is 7.3.
 
On what basis have you concluded that the tank suffers Mg or Fe shortage?
ive attached a photo of the new leaves on a hyrophila corymbosa.
It used to be very green for its first few months until I tried changing lighting.
It seems to have dark green veins & pale leaves on its new growth. Its in high flow too if that's a factor.
 

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you have mentioned that your tapwater pH is 7.7 but that doesn't necessarily mean that the pH in your tank is 7.7. Some aquasoils do buffer the pH quite a bit.
I've noticed my pH is a fraction lower than my tap water at about 7.4
I'm using a soil that didn't have much nutrients in it (Manado) it does have iron though.
At one stage I was thinking of using seachem neutral regulator to buffer the pH at 7.
I don't mind experimenting for a while anyway!
 
ive attached a photo of the new leaves on a hyrophila corymbosa.
It used to be very green for its first few months until I tried changing lighting.
It seems to have dark green veins & pale leaves on its new growth. Its in high flow too if that's a factor.
Hello,
What I can see from the photo you supplied is the yellowing of mature leaves. It is unlikely that this is a micronutrient deficiency as most micronutrients have very poor mobility within the plants. They accumulate in the leaves and they stay there. However, Nitrogen is a highly mobile element. It is also the second most important element and it will move from mature leaves in order to feed the new growth.

It is entirely possible that there are more than on deficiencies, but the most important deficiency, and the one we should suspect in most cases is Nitrogen deficiency. After N is satisfied, if micronutrients are deficient then they will subsequently appear. Therefore, the logical path is to first add N via KNO3 or whichever N nutrient product you have.

At one stage I was thinking of using seachem neutral regulator to buffer the pH at 7.
Attempting to control pH is another one of those time-wasting endeavors. There is no need to control the pH and it won't help this problem. If you really wish to lower the pH then it would be better to simply add peat granules to the filter as this is a more natural way to lower the pH, but again, is completely unnecessary.

Cheers,
 
Thanks for the tips.
I'm going to try using rain water or maybe RO water along with tap water to lower my hardness.
I have been using tropica specialised nutrition for the last month to see if it would help. It seems to be high in N and maybe P but the K & mg values seemed low so I thought it might be magnesium deficiency.
I'll try increasing the dosing for a few weeks & see how it goes.
 
Hi all,
ive attached a photo of the new leaves on a hyrophila corymbosa.
That is definitely a deficiency symptom. Technical term is <"Interveinal chlorosis">.
However, Nitrogen is a highly mobile element. It is also the second most important element and it will move from mature leaves in order to feed the new growth.
Therefore, the logical path is to first add N via KNO3 or whichever N nutrient product you have.
Potassium nitrate (KNO3) is usually where I start, <"for the reason given">.

If it is a nitrogen (N) deficiency you should get a pretty instant greening once you've added some fixed nitrogen. The <"degree of greeness"> and nitrogen content are <"very closely correlated">.

Because you have interveinal chlorosis, rather than the whole leaf being pale, it is likely to be magnesium (Mg) deficiency (and this maybe as well as <"nitrogen deficiency">). Magnesium is also highly mobile within the plant, so you will get rapid greening if (or when) it stops being defiicient.

Iron (Fe) deficiencies also cause interveinal chlorosis, but in new leaves because <"iron isn't mobile within the plant">. When iron stops being deficient it takes a while for re-greening to happen, because it is only new leaves, that grew <"when Fe++(+) ions were available"> that will be green.

Attempting to control pH is another one of those time-wasting endeavors. There is no need to control the pH and it won't help this problem.
Same for me, pH buffers are <"never the answer">.

cheers Darrel
 
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I've started adding the EI dose recommendation for my all in one fertiliser to see if that helps but I've decided to try adding magnesium sulphate as well to see if that resolves the yellowing issues.
I'll see how it looks in a week.
 
The chlorosis in my hyrophila is still roughly the same as it was 11 days ago when I started dosing magnesium. So I was getting suspicious of iron until today I noticed what looks like an iron deficiency in another hygrophila in my other tank. (See attached image) Up until now this one was fully green but the new leaves are pale.
I had been using 50% RO water in this tank since I used to have tetras in it but I started using my hard tap water since I added platys to the tank about 6 weeks ago.
My current iron source is tropica specialised nutrition so I'm guessing the iron isn't getting absorbed due to my high pH. From reading in threads here it seems it likely contains the gluconate salt, is that bioavailable in hard water?
So Today I started using 50% RO in both my tanks water changes to try to lower the pH & hardness. (I think I'll collect rain water too since the RO is very slow to fill!)
 

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That sounds like an easier option!
Would an aquarium shop or garden centre sell iron dtpa or is it something I'll have to get online?
I don't think my lfs has that wide a range of fertilisers but from their website I see they do sell ferropol which seems to be a chelated form. But probably not dtpa.
My brother is gifting me an unused 4 channel doser so I'll probably try dosing iron with it on my main tank.
I wonder would gluconate work in hard water if you dosed it multiple times per day?
 
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