Acceptable calcium level in CRS tank

[sajica]

I've googled and so far I've been unable to find and answer, to what levels of calcium are safe/ recommended in a shrimp tank. Just wondering if anyone might know

Is there an upper/ lower limit?

[fishmosy]

As I understand it (from marine/seawater chemistry) most calcium in water is found as calcium carbonate. As carbonates are pH buffers, adding calcium (as calcium carbonate) will affect pH and alkalinity, so if you go overboard and add too much it could harm acid/neutral pH loving shrimp.

So yes, there are upper and lower limits but I don't think anyone knows specifically what they are. I think your best bet to ensure there are no problems is to ensure you do regular water changes and use a specific shrimp water conditioning powder to provide similar conditions as those found for wild shrimp as both of these will provide calcium and other mineral ions required for the growth of healthy shrimp.

[Triggs]

KH would be one of the things to look out for. If you add too much Ca you will raise the KH

If your KH is within acceptable parameters all is fine really, if it's too low for your liking you can raise it with some Ca and Mg

[Sprae]

Recommended for CRS, KH (Karbonathärte) levels are apparently 0-2, so I'm not sure there's much you can add and not affect that.

[BlueBolts]

A while ago, I self researched, and was determine to conclude on the ideal Ca:Mg ratio for CRS's. Results were a 4:1 to 3:1 Ca:Mg ratio gave me the best results for moulting/colour/thickness etc...

Oliver from Aquotix fwd'd a formula, where test were required for GH & Ca, which then calculates the Mg, thus a ratio can be achieved..(see table below...this is Sajica's WP ...)...GH @ 18, Ca @ 60ppm....Therefore ratio is 60:42 = 1.4:1

[TABLE=width: 347]

GH Value in dGH

[/TD]

Ca in ppm

Mg in ppm

18

60

=

41.82439024

[/TABLE]

The reason I previously asked sajica's his Ca value was that I noticed his shrimps appeared washed out, and although they maybe culls, in my THEORY, it can be improved by ensuring a Ca:Mg ratio of 4:1/3:1.

If Sajica's GH value was lowered to 12, then the ratio would be 50:16 = 3:1

[TABLE=width: 347]

GH Value in dGH

Ca in ppm

Mg in ppm

12

60

=

15.68780488

[/TABLE]

The conclusion is that the Ca & GH level is very high, and if Sajica's tap water is at 12 GH, and the tank is buffering it to 18, then there's a buffering issue within the tank. Theoretically, if the IDEAL CRS GH is 4, then the Ca should be approx. 20ppm, giving the ratio of 3.8:1

[TABLE=width: 347]

GH Value in dGH

Ca in ppm

Mg in ppm

4

[TD]20

=

5.229268293

[/TABLE]

This is where RO water comes into play.......starting with a 0 reading, I use CaSO4 to increase my Calcium, and Epsom Salts to increase my Magnesium.

The formula is ..=((B3*17.86) - (D3*2.5)) /4.1

B3=GH Value in dGH

D3=Ca Value in PPM

The entire motivation for my self research was to get the best colour possible for my .....yes you guessed it, bluebolts!.....I achieved this colour through a 4:1 ratio .....

This is ONLY in my absolute personal research, and tinkering, and maybe full of B!^$S!@&!. Whenever I see my shrimps showing less vibrance, I add some CaSO4, and within 24 hours, they're back to their colour/thickness again. Not a magic potion...low grade shrimps will remain low grade, but may improve colour ....

[durro68]

Nice info the BB. Thanks for taking the time to explain it!

cheers

Greg

[fishmosy]

Thats great info. Do you only add epsom salts and CaSO4 to your RO or do you have your own formula for 'shrimp salts'?

[BlueBolts]

fishmosy - this were pre-salty shrimp days.... I use salty shrimp religiously now. Depending on stock levels, and moulting demands etc, I find that Ca get depleted in shrimps tanks more in comparison to Mg.... So really just a observation I make with my shrimps....i.e. if they start loosing their colour virbrance, I add CaS04. All tanks/environments differ, but this is what works for me...

[sajica]

WOW, thanks for that informative post Marcus :) Do you aim to constantly achieve 3:1/ 4:1 ratio at all times, regardless of GH readings?

Plenty to think about.

[BlueBolts]

Sajica - Yes, that ratio is within my shrimp keepers bible. There's no doubt there many other ratio/theories etc.....but it's definitely worked for me, and more importantly helps explain why things go wrong...i.e. moulting issues, low % of surviving juvi's....etc, BUT obviously there's many other factors influencing moulting deaths etc...but having some workable theories just helps understand the dynamics of WP better, rather then always say WTF did my shrimp die.....I try to combat that with science/theories.....actually I just bombard oliver & Dean with questions and theories !

[fishmosy]

After seeing this thread I've tried to find some scientific papers on the subject. One review paper (on crustaceans, of which shrimp are a part of) in particular suggests that during molting, basically all calcium is depleted from the crustaceans body. So if there is not enough Ca available for uptake there will be problems with post-molting survival.

It also suggests calcium uptake in crustaceans occurs mainly via the gills, so having high levels of calcium in the diet may not necessarily be important.

This exactly fits with what you are saying BB. Did you try higher Ca to Mg ratios, and if so, what did you find?

[BlueBolts]

Mg requirements for shrimps is only minute/minimal, so ratio and Ca levels are more critical....whilst int he midst of teh experiment, and raising my Ca levels, my BB turned radioactive blue, and was found dead the following day ? Oops. So like fire, if you played with chemical, be prepared to get burned....LO...was a very sad and emotional experiment !

[sajica]

DANG!!! But that BB looked smoking hot :)

I'll have you know that atm my GH from tap water tends to flucuate. I've had it as low as 5, but typically it sits around 8 *from memory* GH atm is 9, Ca 60. Eventually I'll be running all tap water through my own DIY filter to soften it for the shrimps, before purchasing a RO Unit. They're pretty cheap on ebay.