# [Wet Thumb Forum]-Balancing K, Ca, Mg. Quotes from an article.



## Roger Miller (Jun 19, 2004)

In another thread, IUnknown wrote:


> quote:
> 
> Another K limiting topic. I wonder if anyone has run tests on this subject. It would be good to post a good article on the subject.


From a hydroponics article titled "A Review of Factors Affecting Plant Growth" by Marianne Ames and Wayne S. Johnson at the University of Nevada, Reno:



> quote:
> 
> Potassium
> 
> ...


and from the same source, a description of deficiency symptoms:


> quote:
> 
> Potassium:
> Older leaves develop marginal browning which can extend into the leaves, and forward curling of leaves.
> ...


The deficiency symptoms are for emersed-grown crops and may appear somewhat differently in submersed growth. I think it's good to review the symptoms of calcium deficiency in particular, because I'm not sure that the problems I've heard people describe really are calcium deficiency.

In my experience, color anomalies in calcium deficiency are fairly mild. Distorted new leaves may be chlorotic, but that is a symptom in stem plants and the shoot end dies immediately afterwords -- usually before the leaves are very old. In Echinodorus and Val, the effected leaves are darker green than uneffected growth

The primary symptom in calcium deficiency is severe stunting of new leaves. especially interveinal leaf tissue. That causes leaves to stop developing before they reach new growth and to be severely deformed. In stem plants, the appearance of distorted new growth is usually followed immediately by death of the tip of the stem.

Roger Miller

[This message was edited by Roger Miller on Tue April 29 2003 at 07:47 AM.]


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## Roger Miller (Jun 19, 2004)

In another thread, IUnknown wrote:


> quote:
> 
> Another K limiting topic. I wonder if anyone has run tests on this subject. It would be good to post a good article on the subject.


From a hydroponics article titled "A Review of Factors Affecting Plant Growth" by Marianne Ames and Wayne S. Johnson at the University of Nevada, Reno:



> quote:
> 
> Potassium
> 
> ...


and from the same source, a description of deficiency symptoms:


> quote:
> 
> Potassium:
> Older leaves develop marginal browning which can extend into the leaves, and forward curling of leaves.
> ...


The deficiency symptoms are for emersed-grown crops and may appear somewhat differently in submersed growth. I think it's good to review the symptoms of calcium deficiency in particular, because I'm not sure that the problems I've heard people describe really are calcium deficiency.

In my experience, color anomalies in calcium deficiency are fairly mild. Distorted new leaves may be chlorotic, but that is a symptom in stem plants and the shoot end dies immediately afterwords -- usually before the leaves are very old. In Echinodorus and Val, the effected leaves are darker green than uneffected growth

The primary symptom in calcium deficiency is severe stunting of new leaves. especially interveinal leaf tissue. That causes leaves to stop developing before they reach new growth and to be severely deformed. In stem plants, the appearance of distorted new growth is usually followed immediately by death of the tip of the stem.

Roger Miller

[This message was edited by Roger Miller on Tue April 29 2003 at 07:47 AM.]


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## IUnknown (Feb 24, 2004)

Thanks for the info Roger, very informative. Well hopefully people will follow up with the different advice given on this forum so we can find out what is working the best for everyone. Seachem wrote back and I am testing out what they recommended. If I see an improvement I will post the results.



> quote:
> 
> >In recent discussion on plant forums I was told that my calcium
> >deficiencies in my plants might be do to having too much Potassium. I
> ...


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## Guest (Apr 30, 2003)

I'm with Greg on this one.
Terrestrial systems are far different.
I've never seen Ca deficiency in my tanks with high K and lower Ca or low K and high Ca.
Some of the tanks have had 30-440+ppm of Ca and the K levels have been over 10-50ppm.
If you are outside of this range, well, I cannot say, but most folks are not unless they try of assume their GH is high when it's less than 3 degree etc.

I think perhaps some folks blame the K in the KCl when it might be the higher Cl ions.
I use K2SO4 along with everyone in SFBAAPS.
We've dosed high K and had low Ca levels for many years, no issues here.

Regards, 
Tom Barr


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## Mortadelo (Mar 14, 2004)

But I use K2SO4, have hard water (lots of calcium) and whenever I overdose potassium sulfate I get what seems to be calcium deficiency (distorted new growth) in some plants. Only when I pull back K2SO4 this symptoms dissapear.

That is what I see in my aquariums, and I know of at least two more spanish buddies that get the same results in their planted tanks.

Saludos.


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## ekim (Jan 31, 2004)

Doesn't boron have similar deficiency symptoms compared to calcium? 
Maybe adding more potassium is increasing the uptake of all nutrients, and leaving boron in short supply!

Just thought i'd throw that out there!


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## Roger Miller (Jun 19, 2004)

> quote:
> 
> But I use K2SO4, have hard water (lots of calcium) and whenever I overdose potassium sulfate I get what seems to be calcium deficiency (distorted new growth) in some plants. Only when I pull back K2SO4 this symptoms dissapear.


Mortadelo,
Do you see any other changes in your plants when you reduce the K dose? Anything that might be attributed to not having enough K?

Roger Miller


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## Rex Grigg (Jan 22, 2004)

ekim,

Good thinking, but boron is really a trace element. Macro deficiency will show up quicker than micro deficiency. And I know that calcium is a micro too, but it a much more used micro than boron.

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## ekim (Jan 31, 2004)

Your right Rex, boron is way down the list, but it still appears in new growth!
I'm not saying that is the problem, just something to think about when diagnosing deficiencies!

I just though i'd add some more "confusion" to the post!


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## Guest (Apr 30, 2003)

I've never had distorted new growth when I added loads of K with high Ca or low Ca for that matter.

If the K issue causes a problem then it seems more likely that it would appear at high K and low Ca values vs the high Ca/high K levels.

Which plants are you dealing with?
What dosing routine and K levels are talkiing about here? 

This goes for those touchy fast growing plants also. Ammannia, Eustralis, Rotala.

I'd try to work on some other nutrient issue.
Let's see what you doing/adding first to see if it's not something else.
I know hundereds of folks that should have issues if this where true so it would be a good idea to do a run down of the what you are adding.

Regards, 
Tom Barr


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## Mortadelo (Mar 14, 2004)

So far I have experienced this problem with Hygrophila corymbosa (two forms), Rotala rotundifolia, Ludwigia arcuata, Altenathera reineckii and a few others I can not remember.

I have experienced this in both soft water (RO water with a little of tap water) and in 100% local hard tap water.

These are my tap water readings (provided by the water company):

NO3 3 ppm 

K+ 2,9 ppm

PO4 137 ppb

Ca 85 ppm

Mg 35 ppm

Fe <= 20 ppb

Mn <= 20 ppb

Zn 28 ppb

Cu <= 20 ppb

B 51 ppb 

Mo Â¿?

Sulfate 247 ppm

Cloride 62 ppm

Na 40 ppm

Bicarbonate 202 ppm

pH 8,1

Conductivity 746 ÂµS/cm (but it has reached 1001 ÂµS/cm recently)

Free Cl 0,34 ppm

fluoride 210 ppb 

I dose K2SO4 to achive 15 ppm K once a week after water changes (50% or more.)

7 ppm NO3 from KNO3 2 x week, this makes 14 ppm NO3 a week plus the potassium in KNO3, so total potassium is around 20 ppm a week.

0,5 ppm PO4 from KH2PO4 2 x week.

Micros from trace element Mix. 0,5 ppm Fe 2 x week.

4W per gallon of light.

CO2 around 30 ppm, sometimes more.


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## Guest (May 1, 2003)

I looked up some of these articles and root nutrient solutions and uptake is different than foliar uptake concentrations.

Think about it.

There are transporters that need to be balanced in order to bring these cations into the plant's roots. The plant has only so many of these transporters also.

My water is softer and has around 50ppm of Ca++. I add the same amount of K2SO4 as you do.
So if someone else is doing fine with it and has good testing kits etc(Lamott) and has measured a number of times, I'd look elsewhere for the issue.

But if it works for you, keep doing whatever you are doing.
Explaining why may prove difficult until you go down one by one each the parameters to see if it's something else. You need to be certain that it's not something else.

Regards, 
Tom Barr


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## Mortadelo (Mar 14, 2004)

I can not be 100% sure since I do not have a potassium test, but I have consciously induced calcium deficiency by adding more potassium to my aquariums. There seems to be nothing weird in my tap water so I think the problem is not there.

Incidentally, this "problem" has become a good way to tell me if I am over dosing K, just like Salvinia tells when iron is low by getting yellower or Hygrophilas tell when potassium is low when they develop holes in their lower leaves.

Saludos.


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## Roger Miller (Jun 19, 2004)

Mortadelo,

Would you please post your experience to the "summary" thread that I started in the main forum. I think it would be very helpful.

Roger Miller


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## imported_Ghazanfar Ghori (Jan 31, 2003)

Ok, heres my experience so far...
Last year I started keeping Ammania gracilis
and it grew great! No problems - grew like
a weed. I wasn't dosing much K at all around
this time. Then I started seeing K deficiency,
and reading up on the topic came up with
the 20ppm. So, I got myself a couple of lbs
of K2SO4 and started dosing 18ppm weekly after
50% water changes. K deficiency symtoms went away. Then I decided to try ludwigia arcuata
and I got curled leaves. Tried it as trades
from several people and new growth would always
be distorted. Added crushed coral to the
filter. No luck. Finally I got sick of 
trying and planted it into my 46G tank (no dosing) and lo and behold - it grew! Nice lush growth - good color and no distorting. 
In the meantime, my Ammania gracilis was getting
slower and slower growth and a few months ago
it got really bad and the new growth was distorted - growing tips died. New shoots
coming off the side would be distorted too.
Couldn't figure it out. H. zosterfolia was
showing whitish new leaves. Everything was
pointing to Ca deficiency - and upon reading
the K - Ca uptake relationship - I decided to
do major water changes and not add in K.

Ammania immediatly responded with better growth.
H. zosterfolia whitish leaves stopped and I got
better growth from all my plants - Gratiola sp.
had a major growth spurt. The change was quite
dramatic. Now before I start running into 
K deficiencies again - I'll start dosing it,
but only 5ppm weekly.

I don't know how biochemistry works, don't care.
I do know from my experience that I tried to
keep everything the same except for K and saw
a dramatic difference. I'll stick with my experiences. Yours may differ - but I'll take Tom's advice - "..if it works for you, keep doing whatever you are doing."


BTW - when I dosed K into my 46G - ludwigia arcuata started showing a slight curling - not
as severe as in the other tank but you could
tell the leaves were distorted. I did a 50%
water change and growth has resumed back to
normal. 
-
Ghazanfar Ghori


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## 2la (Feb 3, 2003)

> quote:
> 
> Originally posted by Ghazanfar Ghori:
> I don't know how biochemistry works, don't care.
> ...


I'm telling you, Ghazanfar, there's nothing like empiric evidence! As a sidenote to all this, I'll let you know that my Eusteralis stellata is still doing well--going on 5 weeks strong and 1 week post-uprooting and -transplanting--since using the R/O Right. The cost may not be worth it for everybody, but if you're big on growing stellata I'd unequivocally recommend purchasing the smallest container of R/O Right available and giving it a short trial. I only dose at 1/4 to 1/2 of the recommended dosage for "very soft water," so it'll last longer.

I'm going to give the low-K trial a go and see if it's NOT a potassium underdose that's causing some yellow spots in some of my plants, but an _over_dose. Will post results some time down the road...


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## Guest (May 1, 2003)

M-
You have 4watt/gal, that's a fair amount, try dosing the KNO3 and Traces(and PO4) 3x a week instead of 2x. Also, try adding 5mls of the traces for each 80 liters of tank 3x a week. 

I think you are running out of traces and or NO3. 

Now about this K/Ca issue:

I've been doing this the same way with the same plants and so have many other folks without issues for many _years_.

PLEASE EXPLAIN THAT.

Your notion is that this exist(K inhibits Ca).
I'm saying this is not true.

It is easy to prove something is not true, to prove that it is true is more difficult. 
Folks blamed innocent nutrients for all sorts of things over the years.

I have the conditions/rotuine and many years of experience in the same set up with the same plants as you folks. Now I don't have this issue and certainly never with Rotala, Hygro's, A. reineckii.
These are easy plants that can take lots of abuse if the NO3 and CO2 are maintained reasonably well.

The tap water varied from super soft(zero GH brought up to 3-5GH with SeaChem eq which has a fair amount of K also along with the Ca) to pretty dang hard(Ca levels in the 440ppm range).

Also, A divalent vs a monvalent cation will not influece one another to the degree you folks are saying(Greg fromn SeaChem explained some of this).

I mean if it's true then why don't I have the same problems?

Magic water? Late night voodoo plant chants?

Come on. I have grown Ammannia (3 species), Lugwigia(at least 6 species), every Hygro, Eustralis and so have many other folks I know and have seen their tanks and speak with often. We have dosed rather high levels of K, using K2SO4. 

The plants do great.
If we don't dose enough or too infrequent then we have issues. Basic mainteance/dosing problem.

Now you might consider if you add a fair amount of KNO3 in your routine, that adding a load of K2SO4 is not needed, but I think it's more an issue of you simply don't need 30ppm. 15-20ppm seems fine too me though. I've done this for many years and never had these issues.But I have gone hog wild with K2SO4 in the past. 

If it was K and Ca interaction why don't I have it? I should according to you folks.

I've seen the same things/deficencies you folks describe with your plants but it was not Ca at all. Mostly infrequent dosing of traces, NO3 etc.

Regards, 
Tom Barr


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## Roger Miller (Jun 19, 2004)

Tom,

If people get better results with lower K doses then I think they should use lower doses. I'm not sure it makes much difference *why* the results are better.


Roger Miller


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## Mortadelo (Mar 14, 2004)

What should I think when I add lots of K2SO4 and new leaves grow distorted?.

I do not dose little K, 20 ppm weekly is a lot, and probably it has stabilized even higher, I do not have problems with this level, it is only when I go beyond this point that some of MY plants go calcium deficient. I would love to know why this happends in my aquariums and not in yours but here comes the fact that I am a law student, not a botanist, so your advice is welcome.


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## Antonio Trías (Feb 4, 2004)

Hi, Tom, My experieces are like MortadeloÂ´s and Ghazanfar ghoriÂ´s ones. Everytime I had one overdose with K I had distorted grows of Vallisneria, Echinodorus, Rotala etc.. Call it Ca deficiency or whatever you want, but tha is a "fact", and the other "fact" is everytime I resolved it reducing my K dose

Best Regards
Antonio TrÃ­as


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## Guest (May 2, 2003)

Well why doesn't it happen in my tanks?
If 10-20ppm works do it. But I cannot agree that it's from K inhibition.

Everything I've seen for many years is counter to this. I have fat healthy stems of Eustralis, Ammannia, Nesaea, Lud acurata all grow like weeds. 

These plants are also NO3 sensitive as well and I know the funniness involved in test kits, especially NO3 kits. These can and will stunt if not well fed.

Harder water will need more traces than softer water.

Also, how do you know what Ca defiency really is with these specific plants?

Not Corn, strawberries etc but these particular plants? This is not an easy question to answer without careful test.

If 10-20ppm works, then by all means do it, but just remember someone else is doing it with 2x the K also so there's a big old problem with this theory. 

But if folks want to modify the levels or recommendations down to 10-20ppm, that should not influence their plant growth at all as far as K+ needs.

Regards, 
Tom Barr


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## Antonio Trías (Feb 4, 2004)

My nitrate levels are always bigger than 10 mg/l. I do not doubt the test are unaccurate, but I thing the good lecture is "you have more than enough nitrates" with these levels.-

I do not know if "this" distorted grow is Ca deficiency or "another" think but is clearly linked with high K levels

Best Regards


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## wetmanNY (Feb 1, 2003)

I don't understand the memo from Seachem quoted by IUnknown. (Is it really from Dr Greg Morin? or just from his office?) It dismisses the possibility that a monovalent cation can compete with divalent cations. The memo mentions K mg/l levels that "work" ("10 to 100 ppm")instead of Ca/Mg/K ratios that "work."

Seachem to the contrary notwithstanding, isn't it generally agreed that sodium (Na+) a monovalent cation, inhibits the uptake of Ca++ and Mg++? Otherwise why would there even _be_ a "sodium adsorption ratio (SAR)" in which the ratio Na:Ca+Mg is recommended to remain <4:1-- as in this excerpt:

"Tobacco seedlings in float systems are very tolerant to sodium. In a recent study, seedling growth was normal at sodium concentrations up to 500 ppm. However, sodium may alter physical properties of the medium and can interfere with calcium and magnesium uptake if the concentration of these elements in the water is less than the minimum values shown in Table 1... A good indicator of the sodium hazard of water is the sodium adsorption ratio (SAR), which is the proportion of sodium to calcium and magnesium. It should be less than 4.0.

"If sodium levels are too high, adding calcium and magnesium will provide increased competition with sodium for plant uptake in both float and overhead- watered systems. In overhead-watered systems, it will also promote leaching of excess sodium from the cells."

--from a NC State U. Co-op Extension Svc. document at http://www.ces.ncsu.edu/resources/crops/tobacco/transplants/AG488-3/

I hope everyone agrees that the fact that these plants were tobacco seedlings is irrelevant.


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## Guest (May 3, 2003)

I've spent some more time looking into this. I still have yet to find much in the literature that may suggest this occurs.

I am also curious as to why I have never seen it when based on this theory I should have.

Now another thing to consider, making larger generalizations on one plant, say Ammannia is not wise. Many plants have particular needs. It's dangerous to apply this on one species.

But I know these plants also and I have almost every plant I could get my grubby hands on over the years. My K+ dosing routine was high for many years and in the last 2 I've reduced it down since I know I simply don't need this much.

But Ammannia is certainly not a model plant for looking into this.

I have found some evidence that is 180 degree opposite of what you are saying with Eustralis for example.
High Ca levels stunt it and K+ is independent.
But am I sure this is the cause? No.

But 10-20ppm of K+ works just as well as 20-30ppm IME also.
I think that's fine. I know from my own experiences that 20-30ppm K+ doesn't cause issues though.

This I have seen with my own eyes for a long time. 

So I'll keep asking:where's my K+ inhibition if this is then reason?

No one seems to be able to address that.

This is as simple as the "PO4 causes algae" well where's my algae then if I have 1.2ppm of PO4 in my tank using both Lamott and Hach test kits?"

Or Fe needs to be maintained ideally at 0.1ppm or algae might occur. 

Or plants prefer soft water or you need RO water.

If someone else is doing well with something figure out why. Then ask yourself is this theory you have really true or not. 



Regards, 
Tom Barr


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## Antonio Trías (Feb 4, 2004)

Tom, unfortunatelly I haven,t any lab tools to monotorize every think, even I dont have any K test, and I cant tell on wich K concentration this happens, but I,m almost sure it is some relation with this anormal grow and the K concentration. If any others variables may have its own influence, may be, but I can not sugest one.


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## Mortadelo (Mar 14, 2004)

Hmmmm, WetmanNY, I have now this ratio for Na:Ca:Mg ---> 61:86:43 (ppm)

Is this ratio correct?. Could be the sodium content too high in relation to Ca?.


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## Roger Miller (Jun 19, 2004)

WetmanNY wrote:


> quote:
> 
> ...isn't it generally agreed that sodium (Na+) a monovalent cation, inhibits the uptake of Ca++ and Mg++? Otherwise why would there even _be_ a "sodium adsorption ratio (SAR)" in which the ratio Na:Ca+Mg is recommended to remain <4:1


To the best of my knowledge, water with a high SAR value is to be avoided because of it's effect on soil textures, not because of it's effect on nutrient uptake.

Not that sodium doesn't have an effect on nutrient uptake. I had severe problems when my sodium:calcium ratios were very high, as have others.

In the cases I know of where sodium could be implicated as a problem the calcium and magnesium levels are very low *and* the ratios are high, e.g. Na:Ca of 10:1 or so. Sodium is implicated only because other people reported being able to grow the same plants in water with the same hardness but with lower sodium levels.

The conditions here where people are reporting possible problems with potassium blocking calcium uptake aren't that extreme. It implies to me that if this is potassium interferrence then the mechanism must be very different from whatever mechanism exists for sodium interferrence.

Roger Miller


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## Antonio Trías (Feb 4, 2004)

Sorry for this question, but How you can measure Na, Ca and Mg concentrations with the normal aquarium test?. Even if you use Gh test, you are not able to separate Mg than Ca


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## Roger Miller (Jun 19, 2004)

You can get expensive GH kits that will distinguish between calcium and magnesium. I don't think there is a test kit for sodium, but I could be wrong.

The numbers I use for calcium, magnesium and sodium come from my water utility, not from a test kit.


Roger Miller


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## Antonio Trías (Feb 4, 2004)

On Spain I never saw (maybe it exists) any GH distinguishing btw Ca and Mg. And to calculate Na concentration on this way is one assumption far away from knowledge, only better than guessing (At least on my country)


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## Robert Hudson (Feb 5, 2004)

Well, Paul K swore to me that he is dosing Magnesium to his tanks and getting great results. He says he has seen significant increase in growth and less algae. Perhaps from an increase in photosynthesis?

There really isn't any way of measuring Magnesium in your water, and he told me the amount he doses is just arbitrary. Perhaps balance between calcium, potassium and magnesium is more crutial than quantity?

Robert
King admin
www.aquabotanic.com


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## Josh Simonson (Feb 4, 2004)

My ammania has been showing calcium deficiency symptoms the last couple weeks. I'd been dosing K pretty liberally as I'd read it was relatively safe and when I first started using it things grew like crazy. I guess the problems started about when I began adding KNO3 and didn't adjust my other K dosing. I'll cut back to only adding K through KNO3 and see if that helps. If not I'll try adding CA tablets to the substrate in a week or two. I'll report back on my findings.

I'll take a few pictures upon request if someone needs some for a help file. I tend to take more pictures of my triumphs than my failings...


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## IUnknown (Feb 24, 2004)

Josh, check your tap water. This problem just creeped up on me recently. Turns out my tap water chemistry has changed recently. I think Fremont is the same. The bay area has switched over to Chloramine and at least for me, the hardness of my water has gone way down. Check out,

http://www.aquaticplantcentral.com/forum/viewtopic.php?t=546


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## Josh Simonson (Feb 4, 2004)

I've been using a DI system since my tap water has kH 12-18dH. I've got it down to 6 in my tank. I've been adding electroright (came with the DI column) which bumps the kH and gH back up from zero. I presume it has calcium in it, but havn't tested my gH in the last couple months. It was 6 or 7 last I looked. I add flourish and occasionaly top the tank off with tap water for micros. My MTS aren't dissolving, so I don't think there's a severe shortage of calcium in the water. 

I'd be thrilled if the kH went down and I could use straight tap water. The city web page says kH 10, gH 13 right now. That's maybe a little better than last I checked. It probably goes up in the summer when there isn't fresh rainwater in the system.


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