CA/ MG thoughts? Questions? - The Planted Tank Forum
 4Likes
  • 2 Post By Seattle_Aquarist
  • 2 Post By PlantedRich
  • 2 Post By Deanna
  • 2 Post By PlantedRich
 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 09-29-2017, 08:16 PM Thread Starter
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 11,868
CA/ MG thoughts? Questions?

I'm thinking through a problem and need to check the group for what you have in mind.
I know that I have a tank in really hard alkaline water. PH starts out at 7.8ish. GH and KH both run near 300PPM. So with that in mind and knowing that the water spends most of it's life running in limestone, I've always considered the CA content to be no problem as it definitely has plenty.
But now I am wondering how the excess CA and an unknown amount of Mg may be working on some of my plants.
I have one specific anubia which has been getting way too much attention as I have sorted through the various ferts which might be lacking.
Nitrate and phosphate are often on the high side but I now have both down.
Potassium has been bumped way up for about a month now using pot sulfate
Extra iron has been tried to almost danger but still this plant looks like it has a nutrient lacking.
Magnesium? How does the excess of calcium effect the ideal ratio we talk about on MG? Too much CA require too much MG? I do not test for CA nor MG as it was always assumed to be there but I would consider testing. The flaw there is that the tests I see seem to be for saltwater. Anybody using salt kits for freshwater testing of MG?
Second thought might be what excess CA might do for the intake of iron, even though I have iron in the water? In the garden, excess limestone interferes with iron intake and we often need to treat plants to keep them green.
Any good thoughts to fill in the blanks?
PlantedRich is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 09-29-2017, 09:46 PM
Planted Tank Guru
 
Seattle_Aquarist's Avatar
 
PTrader: (64/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,298
Hi PlantedRich,

I've been doing some reading on the subject. Calcium, magnesium, and potassium are all utilized as cations (+2 valence molecules) by our plants; i.e. Ca++. Mg++, and K++ are the ones that are important in our planted tanks. From what I have read the cations 'associate' (like attach but not) to negatively charged materials in our tanks such as clay and humus (think fish waste & detritus). The plant roots 'detach' the nutrient molecules from the negative materials and utilize them in the Nitrogen Cycle. A tank can only hold a finite amount of cations which is determined by the amount of negative material. If there is an abundance of one cation, such as calcium it is believed by some that the amount available other cations is reduced (such as magnesium and potassium). I'm not saying this is fact, just what I have found doing research. If you notice the posts I have been making regarding the various deficiency issues one of the causes for the deficiency (again let's say magnesium) could be an excess of calcium or potassium.

Quote:
Interveinal chlorosis. Interveinal chlorosis first appears on oldest leaves.

1. Older leaves chlorotic, usually necrotic in late stages. Chlorosis along leaf margins extending between veins produces a "Christmas tree" pattern. Veins normal green. Leaf margins may curl downward or upward with puckering effect. Necrosis may suddenly occur between veins. Potassium or calcium excess can inhibit uptake of magnesium...magnesium deficiency

When the external magnesium supply is deficient, interveinal chlorosis of the older leaves is the first symptom because as the magnesium of the chlorophyll is remobilized, the mesophyll cells next to the vascular bundles retain chlorophyll for longer periods than do the parenchyma cells between them. Leaves lose green color at tips and between veins followed by chlorosis or development of brilliant colors, starting with lower leaves and proceeding upwards. The chlorosis/brilliant colors (unmasking of other leaf pigments due to the lack of chlorophyll) may start at the leaf margins or tips and progress inward interveinally producing a "Christmas" tree pattern.
PlantedRich and PlantedRich like this.

Roy_________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

75 Gallon, 2X55W AH Supply CF 8800K, 1XFluval F&P 2.0; 45 Gallon Tall, 96Watt AH Supply CF 6700K; 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 and (Calcined) Montmorillonite Clay
Seattle_Aquarist is offline  
post #3 of 7 (permalink) Old 09-29-2017, 11:27 PM Thread Starter
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 11,868
Ouch?? I see the info and that is good but then I think of what it does for getting a really usable idea of how to diagnose what is wrong with our plants. So when we look at a plant and it appears to exactly meet what looks like a lack of some item, is that true? Or is it just the result of having too much of something like CA which then in turn results in the plant not being able to use that one specific item. Makes it a bit more difficult if we see a plant that says it lacks iron, we add iron and it still shows it lacks iron.
Seems like it opens up a whole world of not being able to believe what we see? In a way it kind of makes me feel less foolish for not being able to quickly spot what's up with my plant. But I think I would feel much better if I COULD believe what I see in my plants without having to also figure in that there may be a number of "fake" signs to mislead me.
It really does seem that info may throw out some of the really firm info we see, read, and study about what certain deficiencies look like?
Thanks for the quick input and info. Not sure it helps my mindset but that's a whole different question!
PlantedRich is offline  
 
post #4 of 7 (permalink) Old 09-30-2017, 01:14 AM
Wannabe Guru
 
PTrader: (0/0%)
Join Date: Feb 2017
Location: PA
Posts: 1,290
I've never been a good assessor of plant deficiency symptoms. When a plant gets "bad" in my eyes, I usually go back to the light and CO2 first, then make sure the macros are ok, all the while maintaining micro dosing. However, I haven't had a plant problem in years. So, a couple of thoughts for you to check out as an option to viewing your issue from the standpoint of whether or not your Mg and Ca are good.

As you know, when you test GH, you can't tell what the ratio of Mg and Ca are - could be all calcium (not likely). So, like you, I wanted to know and I have a FW tank. I found what may be the only FW Mg test kit in the World (from what I can tell) that seems to do a decent job of testing Mg only (I calibrated by making my own known mixes of Mg and Ca). It's made by JBL (JBL | Vorsprung durch Forschung) in Germany. I got it via Ebay from one of several British sellers. Make sure you get the FW version and not the SW version. I forget what I paid, but it was reasonable at 2-3 times an API-type kit.

Along the lines of what Seattle_Aquarist was mentioning, also look up "Redox Potential." It speaks, in general, about the ionic charge and a big takeaway is that GH can remain high, but the beneficial charge may be gone. Essentially, you need to revitalize the GH with new Mg and Ca additions occasionally. UV sterilizers also help tremendously with redox. They do other amazing things, as well, and I wouldn't be without one, but it needs to a good one like the Vecton brand. Cheap Amazon types are only good for clearing up a little green water.

Last, if desperate, you could go out and buy distilled water (since you don't have an RO unit) for every water change and add the correct amount of Mg/Ca. Then see if the problem persists over a month or so. That way, you might be able to rule in/out your tap water concern. A lot of people use GH Booster, but I prefer Seachems' "Mineralize" (in the aquavitro line - LFS only) because it is Mg and Ca ONLY. All other boosters include potassium.
PlantedRich and PlantedRich like this.

Last edited by Deanna; 09-30-2017 at 01:22 AM. Reason: correction
Deanna is offline  
post #5 of 7 (permalink) Old 09-30-2017, 01:52 AM Thread Starter
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 11,868
Several lines and theories to think about on what the cause may be.
The tank question kind of fits with a question we have had on several plants in the yard as well. tying the two together is a stretch but then plants in the tank and in the yard do have some things in common. what Seattle is saying fits what I find when dealing with iron chlorosis. It is easy to say it is an iron deficiency but after treating and assuring there is adequate iron, we have to look deeper.
I may be confusing the issue with using the Huntington address but I'm referring to a tank in Central Texas now. I find that I can only have one address and it changes on all past posts as well as current , so I've given up on keeping it current.
In our current yard, the topsoil is only about 12-14 inches deep and then it is often caliche on top of limestone. With that in mind, I find my yard is often suffering from too much Ca. The info above may explain how the Ca prevents the plants from using MG and then FE. What we get are plants that can't use the iron even when we put it down to feed them! Since we can't change the limestone, we find the best is to change plants and try for some which are better suited for the alkaline soil.
Looking a bit, I'm guessing the same is true of my tank. Rather than running short of CA, I'm thinking I add lots back on each water change and possibly not getting enough MG.
I've been playing with this one plant as it is in a small 20 gallon tank where I can manage and change things much easier. But now, I've been through so many things that I declared I was dumping the plant. But then it shot up a new leaf and I'm still in the hunt at this point.
I'm thinking it may be easy enough to try something dramatic like using 50/50 softened water as it is on tap. The downside to that is that the rest of the small tank is looking really healthy and may not like the minor salt left in the softened water. Still we are using softened water on flowers onone side and they seem fine, so that's a possible next step.
First I will go with epson salt to get the MG up and wait and see how it likes that.
I'm glad this is just for fun because I would sure be suffering if it was my job to do better!
PlantedRich is offline  
post #6 of 7 (permalink) Old 09-30-2017, 02:26 AM
Planted Tank Guru
 
Seattle_Aquarist's Avatar
 
PTrader: (64/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,298
Hi PlantedRich,

I think I enjoy the challenge of a planted tank as much as the challenge of breeding various fish species.....it's just different. Something else comes to mind as a result of your previous post and that is PH. High PH, whether in a tank or in soil, will impede the uptake of iron by making less iron available to the plants.

Quote:
Interveinal chlorosis on young leaves

a. Interveinal chlorosis on young leaves with larger veins only remaining green. Necrotic spots usually absent; however, with extreme deficiencies, young leaves are almost white and may have necrotic margins and tips; necrotic spots may extend inward. potassium, zinc or copper excess can inhibit uptake of iron. High pH may also induce iron deficiency....iron deficiency

Iron deficiency symptoms are similar to those of magnesium deficiency, but iron deficiencies occur in young leaves first: Iron accumulated in older leaves is relatively immobile in the phloem.

Roy_________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

75 Gallon, 2X55W AH Supply CF 8800K, 1XFluval F&P 2.0; 45 Gallon Tall, 96Watt AH Supply CF 6700K; 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 and (Calcined) Montmorillonite Clay
Seattle_Aquarist is offline  
post #7 of 7 (permalink) Old 09-30-2017, 01:37 PM Thread Starter
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 11,868
Mind numbing how easy it is to believe we can spot the trouble by simply looking at the plants but when looking closer, it may not be true.
We know the signs of a lack of iron by looking but then it may not be that iron is short in the tank but that the plant can't use what we have added!
I was running on the shortsighted idea that I could find the problem by working my way through the various ferts and watching for progress. That seemed like a patient, slow moving process but pretty simple. But if it is the high PH as the true cause, that gets way more difficult if we talk about actually changing my water.
Not a fan of hauling buckets!
PlantedRich is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome