GH - Ca:MG Ratio

[Aquathumb]

Sorry if I wasn't clear. This was a fresh batch of water made up in a 150l barrel. There was no suluwesi minirels in it. just fresh ro water (0ppm) and 14 scoops of the new tub of saltyshrimp gh/kh+ I just purchased. I found it strange that saltyshrimp gh/kh+ didn't have a good cal:mg ratio for shrimp (1.8:1)

Also I normaly aim for a gh of 8 with my cherries, have been breeding them for almost 3 years like this with no moulting issues. Crs/tbs I like lower around 5-6 tho

[jayc]

Ah!

All good then, if your cherries are used to GH 8.

Just add some ca and test again.

[shrimpstan]

Great read! (Again!)

 

Was measuring my water and seems Squiggles observation of 5ppm of calcium to 1 degree of GH is where im at, as i have GH6 calcium 30ppm my TDS is about 140ppm.

 

Was wanting to measure the magnesium with a sera test kit I bought. Looks like it is in fact intended for marine. Will it still give an accurate reading using only 2ml of water to test on? It a 5 part test.. quite complex compared to most test kits.

 

Im wanting to make sure the water is right and just to know where im at so i can tinker and tweak a little if need be so any help greatly appreciated.

 

TIA :)

[revolutionhope]

hey shrimpstan i cant give you any advice but I'd love to know your findings as I wanted to test magnesium in my tanks too. so good luck and hope to hear some positive report from u :-)

[shrimpaholich]

can i premix the ca:mg powders? say i buy 10kg of calcium sulphate and 2.5kg magnesium sulphate, can i dump them in to a bucket and mix them up good to have my 4:1 ratio? or is it better to keep and dose separately?

[jayc]

4 hours ago, shrimpaholich said:

can i premix the ca:mg powders? say i buy 10kg of calcium sulphate and 2.5kg magnesium sulphate, can i dump them in to a bucket and mix them up good to have my 4:1 ratio? or is it better to keep and dose separately?

Yes, you can premix the powders. But mix it really, really well.

10kg is a massive amount. Are you going commercial? Why do you need so much?

At those amounts you would need a cement mixer.

The mix needs to be kept very dry, and moisture will cause it to absorb water and turn the powder into a messy clump. Another disadvantage of making such a huge batch.

[shrimpaholich]

well i bought them amounts lol. im going to package it up and maybe see if i can get a lfs to carry it and get rid of it with shrimps they sell. they most likely wont, but i can atleast have it and start an inventory of my own for when i start breeding shrimp. or maybe even sell on ebay. i dont like doing anything on a "small" scale. doing things in bulk saves $$$

[nerowolfe]

New to keeping CRS, and I have been on a steep learning curve.

Tank originally set up using treated tap water, to cycle, then all water changes using RO aged with peat, (pH of supply 7.2 - 7.4), or rainwater (pH 6.9). Top offs using pure RO. I am using mineral balls, IAL, Alder cones. The substrate is ADA Amazonia.

I tested my tank, and got the following:

Ca = 40ppm

gH = 80ppm (or 4.47 dGH)

Using the formula, I get a negative value for Mg, so the ratio is: -8.4:1

I am expecting delivery of Salty Shrimp Bee Shrimp Mineral GH+ today, and I'll start using it to reconstitute the peat treated RO I use for water changes. What else should I be doing to bring the ration back into line?

 

[KeenShrimp]

Hi @nerowolfe,

SaltyShrimp has a Ca:Mg ratio of 3.79: 1. This is exactly in the sweet spot. By mixing the SaltyShrimp to the desired GH that you prefer to match your setup, it is a very safe option to just keep doing your water changes with the salty shrimp and the deficiency will equal out over time if it is not a heavily planted tank.

There are very successful breeders that do not worry about this ratio at all: @ineke I hope you do t mind me using you as an example?

If you have many plants in the tank, they use more Mg than shrimp as there is a Magnesium molecule central to every chlorophyll molecule in the plant cells. I suspect this is not your problem, instead, the mineral balls might be releasing too much Calcium. For your GH of 4.47, your Calcium is a bit too high. I suspect that plants might not be your problem. I would recommend taking out a few mineral balls as if you want your tank to stay stable at a GH of 4.47 that you currently have, your Ca should be 22.5ppm ( you measured 40ppm)  and Mg 5.79 approx giving a ratio of 3.88:1.

In your situation it is not advisable to correct this imbalance by adding MgSO4 ( remember that shrimp don't like change), also known as Epsom salts ( Magnesium Sulphate). The reason why this is not the correct course of action in this case as your Calcium is quite high already, thus by just adding Epsom salts, your GH will go up quite a bit and you will possibly end up losing a few shrimp with the GH change.

So, by mixing Salty Shrimp to your GH of 4.47 for your water changes and by removing a few mineral balls, your ratio will correct itself safely and naturally.

[jayc]

@KeenShrimp has hit it on the head spot on.

 

 

@nerowolfe, what have you been using to remineralise the RO and R/W (rainwater) so far if you didn't have salty shrimp?

[nerowolfe]

Thanks @KeenShrimp I'll do that, and bring the ratio in line slowly. Oh, the tank is quite well planted, Anubias, Crypts, Java fern and Water wisteria. (no CO2 - low tech), so that may be having an effect on the magnesium levels, which I'll be monitoring closely from now on.

@jayc I used a little Continuum GH+, which does have calcium & magnesium, but I must admit i didn't use it all the time in the peat aged RO water, until now I was only testing gH and was focused on that and the pH, which I am slowly bringing down into the high 6s, using peat in the filter and the peat aged RO. Now I am aware of the importance of the Ca:Mg balance/ratio, I'll start getting it back into the right ratio.

The good news is that my new CRS have settled in nicely, active and feeding, and exploring the tank.

[nerowolfe]

Another question .. what test kit are people using to test for Ca? I ask because the freshwater one that came with my Nutrafin (Hagen) master kit, only has an accuracy of 20ppm increments. So a colour change after 2 drops of reagent can be anything from 21ppm to 40ppm! Kits for saltwater are calibrated for much higher ppm range, as suits seawater, and are quite specific as being for seawater only.

[revolutionhope]

Hi nero you can usually double or triple etc your water volume and then divide the result to obtain a more accurate result with this style of testkit. Alternatively get the api which is what most of us use. (Including bluebolts the author of this thread)

Love n peace

Will

Sent from my SM-N920I using Tapatalk

[nerowolfe]

I looked at the API, but again it has an accuracy of 20ppm, nothing in between.

I am thinking to test Mg instead. There is a good freshwater Mg test kit from JBL Germany, and it measures from 0 - 10mg/L (ppm), and >10. It then seems to me that you could then calculate a more accurate Ca level.