# GH, KH, Eco, & Onyx



## heidisue (May 3, 2006)

I combined Eco-complete and Onyx sand for substrate. My GH went from 3 to 7 in 5 days and my KH went from 2 to 4 in as many. After a water change things mellowed out for a bit but they are climbing again. And my pH is holding at 8. (I know, I know, I'm getting Excel tomorrow). But I'm wondering how long the substrate component of this equation is going to take to even out. And given that the tank is still finding its legs, what is a reasonable ppm to shoot for in terms of CO2? At least for now? 

I'm not completely confident about my understading of some of the chemistry but my fear is that 
a) if I adjust the hell out of the tank it will get somehow dependent on all this tinkering and 
b) if I don't, my fish will leap out, all mutiny-like.


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## Bert H (Mar 2, 2004)

Eco and onyx are known to effect kh/gh. While I haven't had any experience with onyx, I do with Eco. In my tanks it took a couple of months before the effect completely disappeared. From the numbers you show, I wouldn't worry too much about it. Your kh/gh numbers are quite acceptable. If you're going to be using Excel as your carbon source, I wouldn't worry too much about your pH at this time either.


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## gtrewjr (Feb 4, 2006)

I'm using a mix of Florite and Onyx sand. I have the same thing happening in the tank (it's about 4 mos old now). The drift is pretty mellow so I don't worry about it. 

A 50% water change puts me at about 40-44 ppm CaCO3. after about 2 weeks I am around 64 ppm CaCO3. I'm guessing that over time this will change less, but even the drift that I have now is not really an issue. However, I have not gone more then 2 weeks with out a water change so I ahve no idea how high it would get, I'm guessing it still would not become problematic.

Grady


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## banderbe (Nov 17, 2005)

I like how Caribsea's website says of Eco-Complete "will not increase carbonate hardness *in the long term*."

Gee, thanks!


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## jbierce (May 11, 2006)

The few times I've used Eco-Complete I've noticed a sharp increase in GH over the course of a few days; but it seemed to level out within a week. I've never seen an increase of KH though; and since I've never used Onyx I can't really comment on it.

JBierce


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## Newt (Apr 1, 2004)

Here is a chart that will help you determine your CO2 level based on pH and KH.


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## erik Loza (Feb 6, 2006)

How do your fish and plants look? My substrate is similar to yours: 50/50 Onyx with some sort of fine basalt gravel that was leftover from another tank over a layer of Dupla Ferti-Plant mixed with Eco-Complete and powdered laterite. I do have a pressurized gas system and pH controller but have never really tested my hardness. Some plants didn't do well for me at first (too much light in my tank for Anubias, I think..) but I need a weed whacker for the rest and I never really lose any fish. Just lots of water changes to keep everybody happy. Good luck.


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## heidisue (May 3, 2006)

*funny you should ask*



erik Loza said:


> How do your fish and plants look?


I just came back from a weekend away and they look better than ever. Maybe they just needed me to leave them the hell alone so they could grow in peace. 
They definitely needed a grace period to settle in but now the tank is almost a month old and I'm starting to get a lot more new leaves and roots. When I got home I was surprised how happy I was to see my tank; I really missed it!


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