Negative effects of high/low ALK/CA/MG?

Hey all,

Please don't stone me if this is a dumb question. Could someone please give some general feedback on the negative effects that a high or low level of the 3 main extended params (ALK/CA/MG) are?

I know there are lots of variables, but I maintain those extended params but don't really fully know what happens when any of them gets too high or too low. Similar to Desmond entering the code and pushing the button every 108 mins.

Would love to know the general effects of too high/low on corals and/or fish for the 3.

Thanks for any input,

 

This thread has been moved to the Water Chemistry forum

 

I'll talk about Mg.

Low Mg will make it near impossible to keep Ca and Alk in line.


If your Mg is too high (and assuming it didn't sky rocket hundreds of points in a day) you won't notice a lot of impact at first. Some things might not like it but in general it will basically stunt growth till it comes back down.

Having high Mg (say 1650+) will also make Ca and Alk tests pretty unreliable (this has been confirmed in another thread). Probably impacts other tests too. Basically, the solutions won't mix right.

It will only get so high before it starts to bind to the rock and substrate. So you will find doing a water change will lower it but it will climb back up. It will take a few WC to get it down. (If it gets up to around 17-1800).

 

With regard to magnesium. I have seen reports that hobbyist treating for Byropsis with elevated magnesium levels saw problems with their snails. The levels were high around 1800 ppm.

With an elevated ALK, you might see burnt tips to sps and tissue regression with lps. As Peredhil posted the values are inter-related. If you are attempting to run a ULNS you will see the adverse affects of ALK at lower levels, it's advised to keep the ALK more closely around 8- 9 rather than 10-11.

There is a recent thread where a member had an elevated Ca level somewhere around 560 ppm I believe, and a much lower ALK level than desired, which caused noticeable tissue loss to the tips of his sps.

I struggle with the relationship and interactions between CA/ALK/MG and can never remember the ratios or the typical uptake rates. I do however run my tank at higher levels with Ca around 500, ALK 10-11 and Magnesium around 1500. If I go much above that I notice whiter tips, not burnt but almost like am over clocking my corals. If I go below those levels I loose ground quickly and can not keep up with the uptake. This is probably related to the size of the tank and the corals I keep.

 

Too big a rise in magnesium can also bleach corals.

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OK I put my stone down.. LOL.. Just kidding, still in my hand... But, seriously. ;D

Too low and your coral, invertebrates, & fish will suffer. For example on CA, it is the building block that coral requires to grow, just as we need it for our bones.

Severely depleted levels of magnesium (below 800 mg/L) can cause depressed pH levels and an inability to maintain proper calcium levels.

Alkalinity is what provides the correct and stable pH for a reef aquarium, if maintained at sufficient levels. A correct and stable pH, i.e. nonfluctuating, is important for the health of an aquariums inhabitants. Many authors state that alkalinity is important as it is a measure of the ability to resist a drop in pH. This is true, but it is only half of the story. It is also a measure of the ability to resist an increase in the pH, i.e. the "buffering" of the water works in both directions. Some components of the alkalinity buffer system are also utilised by organisms, such as hard corals, and so have to be present in sufficent amounts for good health and growth. Additionally, the higher the alkalinity, the greater the ability of the system to absorb the additionof an acid or a base with only small change in the actual pH.

Too much of anything is not good either. Please define too much? Since like others we tend to run those elements a little higher. For example, my parms are CA: 550, MG: 1500, Alk: 10. For example VERY high levels of magnesium can kill some invertebrates "turbo snail and brittle/serpent starfish for example"

 

LOL.. Too me a bit to post since I'm at work & had to find the right LINGO to explain.. LOL!!

 

This is a good read...
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com

 

great insight everyone, I really appreciate it! I def have basic knowledge of the extended params but wanted to get some more insight. I'm having a bit more trouble sustaining them in my new tank and knowing the ill effects is a good thing as my levels have been fluctuating a bit too much.

@ComputerJohn in terms of "too high" it's variable, hard for me to say an exact # but I was just wondering how bad, if at all, any of them could be if left unchecked.

 

Running too high (Alkalinity, Ca, Mg, and Sr) will cause corals, bi-valves, etc to use too much energy. Remember, these elements are not good for them....in fact, the best way to describe them would be poison. Millions of years of evolution have created a use out of them getting rid of these poisons. However, they are used to a certain amount and it doesn't make sense to force them to artificially increase those elements to get faster growth (within reason).