High K+ and very nice Ammannia

[Plantbrain]

Erik informed me that his K+ was around 100ppm during this time of the photo. The Ca++ was fairly low, the likelyhood that the folks are having issues due to high K+ seems slim to none.

http://showcase.aquatic-gardeners.or...ol=2&id=18

Hope this proves my contention a bit more and shows that folks are not correct about the high K+ causing stunting.

I'd like to know what is causing the issues, but I know it's not K+. I am almost finished with the Ammannia test at 40ppm K and things look dandy at almost week 2.

Regards,
Tom Barr

[PeterGwee]

Tom, how about testing the ratio between calcium and magnesium then? Folks here that are having issues often dose loads of magnesium and no calcium. Perharps its the magnesium overwhelming the calcium that is causing this? Singapore's tap water GH is at 3 and a ratio of 5:1 (Ca:Mg)...data provided from PUB upon request.

Regards
Peter Gwee

[Sleepy_lancs]

I notice that entry added CaCO3 as part of the stuff he adds. Maybe thats why. Thats my 2 cents worth

[Plantbrain]

We generally don't add much Mg, Ca yes, Mg not a lot.
Erik and most of the folks in sfbaaps group have done the similar routines and discussed the effect, even if very subtle with each of our routines.

Much of the advice I often give is based around those past discussions over the years.

I don't think there's much issue with ratios etc, as long as large extremes are generally avoided.

So if the Ca is 30ppm or higher, you are safe, if the Mg is 8-10ppm or so, you are fine, K+ in the 10-20ppm range you are fine.
Low Na/sodium.

The point of this post is to show that high K+ is not a factor in the bantwer over K+ blocking Ca.
I think some folks added way too much K+, or that even though their tap water sometimes say 30ppm etc, sometimes the levels drop. Antonio in Spain has hard water and says they have the same K+ issues which seems counter.

But folks should lower the K for at least two reason for sure, one, you don't need 20-30ppm, 10-15ppm is fine.
Two, it's nice not to have to find/buy K2SO4 if enough is added via KNO3.
One less thing to dose.

But if there's an issues that appears to fixed by adding less K+, keep doing it till there's a more definite cause is determined.

SF has very soft water(almost pure).
see www.sfbaaps.com and read Steve Dixon's article.
Regards,
Tom Barr

Regards,
Tom Barr

[juggler]

Erik's Ludwigia looks superb.

In my current tank, when I was dosing like 20ppm K and 5ppm Mg per week, the leaves of my Ludwigia brevipes curled downwards. My MM also started shrivelling. But other plants remain OK eg. Echinodorus, Anubias.

I have some coral chips in my filter as well to supply Ca and Mg. gH maybe about 9~11. kH about 2~4.

After I stopped Mg, things improved after a few weeks. Subsequently, I reduced K to 10ppm and things were still OK.

Perhaps you can experiment with adding in 5ppm Mg into the high-K tanks to see if there's any adverse effects. Try not to put in extra Ca at the same time.

I relate my past observation after discussing this K:Mg:Ca relationship: My first tank was "wrongly" laid with a coral chips substrate. That means high Ca and Mg. Even when I dose 20ppm K and 5 Mg per week, I don't observe any adverse effect. I suspect the high Ca helps to balance things.

Or perhaps this K > Mg > Ca affects certain plants only?

[FC]

Since the first time I use the K2SO4 and MgSO4, I was very sceptical about the relatively high SO4 that they brought about. I doubt the plant could consume that much of SO4 which I suspected that it eventually built up excessively over time. With the usual K & Mg dosage, SO4 would easily climb beyond 100ppm after 2 weeks, assume water change every 2 weeks.

When I first dose K2SO4, MgSO4 together with other nutrients, the plants benifited; the leafs were beamingly shine (like being waxed). I suppose the SO4 did the trick. However, with months of built-up, things changed. My stem plants started to loose leafs. I do not have Ca deficiency as I already knew it coming and I countered that with coral chips in my filter.

Jugglers' experiences seems to match my encounters where the addition of K2SO4 (45%K vs 55%SO4) coupled with MgSO4 (SO4 vs Mg is 4:1) just tipped over the SO4 scale.

Regards,
Freddy Chng

[cks]

FC,
So despite the debate on high K , you suspect that SO4 is the culprit and not the high K content per se

[FC]

Dear cks,

So despite the debate on high K , you suspect that SO4 is the culprit and not the high K content per se

I think so.


K.F. (Juggler),

I still dose MgSO4 but in less amount (about 2ppm per week). I am nearer to my target of changing water once a month while keeping the water condition balanced and clear. For that, MgSO4 is something I cannot lack, along with coral chips and other usual nutrients.

Regards,
Freddy Chng

[blackBRUSHalgae]

Erik's Ludwigia looks superb.

In my current tank, when I was dosing like 20ppm K and 5ppm Mg per week, the leaves of my Ludwigia brevipes curled downwards. My MM also started shrivelling. But other plants remain OK eg. Echinodorus, Anubias.

I have some coral chips in my filter as well to supply Ca and Mg. gH maybe about 9~11. kH about 2~4.

After I stopped Mg, things improved after a few weeks. Subsequently, I reduced K to 10ppm and things were still OK.

Perhaps you can experiment with adding in 5ppm Mg into the high-K tanks to see if there's any adverse effects. Try not to put in extra Ca at the same time.

I relate my past observation after discussing this K:Mg:Ca relationship: My first tank was "wrongly" laid with a coral chips substrate. That means high Ca and Mg. Even when I dose 20ppm K and 5 Mg per week, I don't observe any adverse effect. I suspect the high Ca helps to balance things.

Or perhaps this K > Mg > Ca affects certain plants only?

OLD OLD THREAD anyway...


Hi juggler, so could I confidently say that the problems with your Ludwigia brevipes and MM is due to low CA?

[juggler]

Nowadays, I keep coral chips in my filter for the source of Ca and Mg. I never dose MgSO4 nor add baking soda (NaHCO3) for kH. I continue to dose K2SO4, K2HPO4 for K and P respectively. As for N, the plants depend on fish poo.

So far OK. Won't say it is algae free, but is under control most of the time.

[Plantbrain]

Use dolomite instead, it has Mg and Ca and KH.
Coral chips are just CaCO3.

SO4 is really not going to be the issue either.
The high levels in my old Tap water was around 50ppm. I grew Ammannia that was well over 15cm in diameter, even in low light.

The K+ is typically added via K2SO4.
A few folks use KCl.
High Cl might be implicated, but I have not tried that one.
Still, the tap was 40ppm Cl, the well waters where even higher.

I think it's unlikely you folks have such hard tap waters in SG. The tap I now have comes off the Sierras granite water shed and is extremely pure. SF has water from these sources as well, while just about 20-50miles away, the tap might be 10-20X harder from well ground water.

Regards,
Tom Barr

Regards,
Tom Barr

[juggler]

Hi Tom, what about sea shells? I also use them. They have both Mg and Ca, I suppose?