Water Change and Mg Dosage Survey

[geoffrey]

Hi All,

Could everyone help by providing feedback for the following:

Water Change : Weekly/Fortnightly/Monthly/?? ( ?? - please specify)
Volume changed : 25% / 50% / ??
Dose Mg : Yes / No
ppm/week : ??
CO2 buffer : Coral / baking soda / ??

Thanks.

[PeterGwee]

Water Change : Weekly/Fortnightly/Monthly/?? (Weekly)
Volume changed : 25% / 50% / ?? (50%)
Dose Mg : Yes / No (Some from flourish?)
ppm/week : ?? (N.A)
CO2 buffer : Coral / baking soda / ?? (Baking soda as buffer)

[kadios]

Water change: 1/3 for 3 ft
Mg dose: Mg powder 1/8 teaspoonful(u may try epson salts)
ppm: Dunno
Buffer: Baking soda to keep Kh high arnd 4.5 - 5, about 1 spoonful to maintain

[kadios]

Forgot to add that 1/3 change weekly

Cheers!

[illumbomb]

Water Change : Weekly
Volume changed : 35%
Dose Mg : Yes (with MgSO4)
ppm/week : 5ppm/week
CO2 buffer : Coral

[naturetan]

Water Change : Weekly for 2ft
Volume changed : 50%
Dose Mg : Yes
ppm/week : 3ppm/wk
CO3 buffer : Coral for both Ca & CO3

[juggler]

Water Change : Weekly
Volume changed : 50%
Dose Mg : Yes
ppm/week : 1ppm/wk
CO3 buffer : Coral chips for Ca and CO3

[geoffrey]

illumbomb; naturetan; kadios,

Do you guys experience Ca deficiency symptoms? Especially illumbomb, do you?

[naturetan]

For my case, before I dose Ca and Mg, I've problem with several of my stem plants. Leaves get distorted & shrivelled at the tips, especially Rotala Indica, Macrandra and few others. That time I was dosing about 30ppm of K for macro.

Then I started dosing Ca & Mg. Reduced K to about 10ppm. Lower leaves started to get holes and melted. The same problem if I don't dose K. However, distortion is gone.

Now, I increased my total K dose to 25pppm. After several weeks of monitoring, I've yet to find any distortion or melting.

[geoffrey]

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On 6/12/2003 12:38:50 PM

For my case, before I dose Ca and Mg, I've problem with several of my stem plants. Leaves get distorted & shrivelled at the tips, especially Rotala Indica, Macrandra and few others. That time I was dosing about 30ppm of K for macro.

Then I started dosing Ca ...


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NatureTan,

You started dosing Ca later by adding Coral? Before, were you using baking soda as buffer?

But 25ppm versus 30ppm of K, IMO not very significant. Could your adding of coral (Ca) actually resolved the Ca problem? Please post if you see Ca deficient like symptoms with your current regime. I am trying to find out if Mg is actually causing Ca deficient like symptoms.

Not until the begin of last week, I was dosing 5ppm Mg per week on top of what the tap water (change water fortnightly then) and corals provide. This gives problem to my Lobelia. Through this survey, I hope to see a relationship between excessive Mg and a possible Ca deficient like symptom.

I really hope everyone could help by posting their observation.

[Simon]

geoffrey, y dun u asking the members to include brandof fertilizer/PMDD, that way u can find similar things with nutrient deficiency

[geoffrey]

Simon,

I am suspecting that those who do frequent water change (weekly or fortnightly) and not dose Mg will not have Ca like problems. IMO, tap water provides enough for a week or two.

Conversely, those who do frequent water change (weekly or fortnightly) and dose Mg (approx 5ppm/week) and have coral as CO2 buffer will have Ca like problems.

There are people who dosed Mg yet do not have Ca like problem. I am suspecting that they are changing small volume of water over a long interval of probably a month or so, or they may not be using coral as buffer. Hence, Mg is needed to supplement what is provided by the tap.

So I am looking along this line and that is why I did not add other stuff. In fact, I am very interested with those using Mg and yet do not have Ca problem.

So, Simon, what is your regime?

[vinz]

Geoff,

I'm getting intermitten Ca deficiency problems and my GH is around 15(+/- 5) dGH. I'm suspecting excess Mg too. Deficiency symptoms are non-conclusive. The only Ca I've added is from Equilibrium which also contains Mg, so that doesn't help if Mg is a problem. I'm thinking of getting some dolomite or maybe some of calcium pills this weekend to supplement the tank.

If you read the various forums/websites, the recommended Ca:Mg ratio range from 2:1 to 4:1.

Water change: 25-30% fortnightly (except when I'm resetting the tank which would be 50%/week)
Mg: experimenting. Mostly likely change to dosing equilibrium once I get the GH down.
pH buffer: Baking soda

[Simon]

Water Change : Weekly
Volume changed : 50%
Dose Mg :No
ppm/week : ??
CO2 buffer : No
Fertilization: TMG, twice weekly 10ml, KNO3 1/4 teaspoon (twice), K2SO4 (3/4 teaspoon once) a few grain of KH2PO4 (twice)

never had any sign of ca deficiency before

[geoffrey]

Vinz,

I'm getting intermittent problems too, but lately it worsen and my gH is >20!! Coral is confusing the troubleshooting because it has Mg, like equilibrium.

I doubt its a deficiency because I push almost everything to a high. Ca is the only thing I can't push because I use coral. And I believe it's a waste to add more Ca through other means just to meet the Mg:Ca ratio that may have arisen because of my excessive dosage of Mg, not meeting the Ca ppm provided by my coral.

For now, I am lowering it to ~1ppm per week with 50% water change weekly. While I am doing this, I want to be conclusive in nailing the Mg bugger.

[naturetan]

Yes, I used baking soda before that. Now, I use coral for Ca and KH. Not using anymore baking soda.

The thing is that there has been suggestion that Ca deficiency is caused by high K, that's why I reduced to 10ppm. But after it start showing K deficiency, I increased it back to 25ppm. I'm all using Dr. Mallick product, including micro.

I'm not sure whether after about 3 weeks of monitoring, it can be conclusive. If so, I'm sure that adding Coral and MgSO4 solved distorted leaves problem. But at what proportion that it can affects, I've yet to experiment with it. Due to external filter high flowrate, I'm only putting just a bit of coral to supplement it, giving me an average of about 6-8GH.

[geoffrey]

Noticed that lower gH don't have this problem too. Vinz and myself have pretty high gH. Juggler what's your gH lately after you lower you Mg to 1ppm? Below 10?

[vinz]

K cannot directly affect (i.e, no blockage) the Ca uptake. I suspect it's because the high K allows the plants to grow more, but the Ca from our tap water is insufficient. From the recent posts, it seems the Ca:Mg ratio in our tap water is ok, but the levels are simply insufficient for high-growth/less-water-change tanks.

Geoff, I suspect our tank's Ca:Mg ratio is way off. The high GH is probably due to low plants absorption of either due to the imbalanced ratio. Maybe you can consider taking out the coral chips, reduce the GH with water change and then use Equilibrium instead.

I've read that Mg affects the plants usage of Fe. I'm not sure of the mechanism, so I'm wondering if higher Fe dosage may help the plants use up Mg and thus increase the uptake. Got to go research this one.

[juggler]

My gH is around 10 because of the coral chips.

[naturetan]

Forgive me for my earlier post. I just recalled that I started dosing KH2PO4 quite near to the time I began dosing Ca:Mg, due to invasion of algae. So I'm not particular sure which is the one (PO4 or Ca:Mg)that solve the problem for distorted leaves. If people whom have such symptom could monitor their PO4 level, that will be good to dispel such possibility.

I agree with Vincent, my tank is about 0.9W/l for 2 ft, despite 50% water change per week, it will still show such symptom quickly if I stop dosing it.