Question on Dosing Mg + Ca

I've been picking up more and more dosing of individual ferts of late and seeing a lot of improvement in my plants. LOTS of K and PO4 has kept the algae at bay. It hasn't done away with the BGA, but it's keeping it in check, surprisingly.

Now I want to try dosing Mg and Ca to see if my reds will improve. I have CaCO3 and MnSO4 and read in the hardness thread of a 4:1 ratio, but I didn't really see what the dose per 20g should be?

I did dose 1 tsp CaCO3 to ¼ tsp of MnSO4 in my 75gs -- is that too much? The water gets REALLY cloudy and takes a while for it to clear up. I was worried about the fish at first, but dang if they just shoot through the "clouds" and start spawning behavior! *ALL* three tanks? Different types of rainbowfish? Are magnesium and calcium some sort of aphrodisiac to rainbowfish or something? My water must be way too soft for these guys.

Anyhow, if someone can gimme an idea of what I should be dosing, I'd appreciate it. Tap water is as thus:

GH 6
Ca 40
Mg 1.7 (calculated)

MAN! pH 8.2!!!!!!!!!!!! What the heck is the water company DOING? My tap water has gone from 7.4 to 8.2 pH. Sheesh! Chloramine gone, chlorine only now. Nitrates 0, down from 7ppm. KH 4, up from 1-2 dKH (at least THAT is an improvement), PO4 2.0 not much change there.

I need to get a water report.

Roan

djlen said:

Roan - I will give you a quick history of my experiment with calcium.
I went for years not dosing any extra at all.
There was a ground-swell of calcium dosing about a year ago and it seemed as though everyone started dosing it.
I was talking with Tom Barr and he recommended dosing Equilibrium. I figured I'd give it a shot and tried it, seeing no change in plant growth or color over a 6 month period.
I've always dosed Mg heavily because it's been good to me and so I started playing with ratios of Ca/Mg and increased the Ca (CaCl) incrementally until I got to a bit over the 4:1 ratio.
During this period a couple of my plant species that occasionally go dormant, did so and I didn't think much of it. I then noticed the Crypts. in all my tanks were not looking crisp and/or waxy which are my signs of good health.
Over time I came to realize that the Ca dosing was probably negatively affecting just about everything. I started cutting back on the Ca and everything started to improve. All of my 'dormant' species came out of 'dormancy' and the tanks look better than ever. I'm still dosing Ca, but only at 1:1 with Mg at this point and it seems like a proper mix for me.
This has just been my experience with this nutrient.

Len

Click to expand...

Len,

Thank you very much for posting. Do you happen to know what your Ca was before you increased it?

The reason I decided to try increasing my Ca, "in tune" with the Mg I have increased, was based on the information in the thread that Daveedka and Reiverix started:

http://www.aquariacentral.com/forums/showthread.php?t=65367&highlight=hardness

and also because of the differences I noticed between my CO2 injected tank and my one non-CO2 injected tank:

All of my rainbow tanks have Vallisneria var. Americana, which looks almost exactly like Vallisneria natans -- the broad leaf version found in PNG, not the narrow leafed one -- in them.

All of those tanks, except one, are CO2 injected. They all, except that same one, have crushed coral/aragonite in them to stablize the KH. The coral, of course, releases calcium carbonate into the water as it dissolves (correct me there if I'm wrong, please).

I've measured the calcium in all the tanks and I have been tracking it. The two tanks with the highest CO2 in them have the most calcium in them -- around 160ppm. The vals in those two tanks are very broad leaved, as they should be, and a wonderful green color. All the plants in those two tanks look really nice, but could be nicer. They definitely look better than in the other tanks.

The vals in the tanks with less CO2 are not as broad leaved and are paler in color -- around 60-100ppm Ca. Edit: I just noticed now that the newer leaves in those tanks are crinkling and twisting like the ones below.

The vals in the tank with no CO2 and no crushed coral have started to grow very transparent, and in a "cork screw" shape, very similar to what John was describing in one of his posts. They look sick. Even the older leaves in that tank have developed ripples in the edges of the leaves. The calcium in there as is with the tap water, 40ppm.

I want to get my calcium in all the tanks up to at least 160ppm, but I don't want to do it by using CO2 and crushed coral.

In fact, the reason I chose CaCO3 was because it was the closest to aragonite and I like the idea of keeping what's already there and working well.

To be honest I don't know what the difference really is, benefit wise, between calcium carbonate and calcium chloride.

I do have a couple of cyperus helferi in the high Ca tanks, but haven't noticed any detremental effects from the Ca.

Comments?

PS: I also use Barr's Booster, which is why the Ca in the tanks is running on the "high" side. I tried Seachems but I can never get that stuff to dissolve properly and am fed up with it. I don't like loose particles floating around my tanks.

Roan

Yah, it was rather a low dose, but geez, that's an AWFUL lot of stuff to dump in a tank like that

Guess I'm still a little squeamy on some aspects of the ferts.

Roan

I just sent Greg an email asking for clarification on that. I ordered MgSO4, Magnesium Sulfate and he sent me MnSO4, Manganese Sulfate. He doesn't have that listed on his site.

What's the difference?

Roan