Water Chemistry

[Joel]

Hi guys,

I am currently keeping a small colony of WC Mpimbwe.

I did a few water tests on my tank just before my weekly 50% water change and I get results as follows:

- pH = 8.0
- NO3- = 10mg/L
- GH = 140mg/L
- KH = 40mg/L

I'm pretty happy with the pH although it could be a little higher from what I understand from readings about pH in Tanganyika. From memory I think it was suggested around 8.5-9 is ideal. I don't think I will bother trying to raise it.

I am very happy with the Nitrates being as low as they are after a week. I could never get them this low on other tanks in the past...

The GH seems a little low. I'd like to raise it.

The KH seems alarmingly low! I think I need to raise it.

To give a little background on my setup:

* Tank is a 5x2x2
- Substrate is pool filter sand (the non buffering type)

* Filtration
- 2 air driven sponges within the tank
- 3ft baffled sump contains:
- Kaldnes K1 media
- Japanese filter matting
- Coarse black filter sponge
- Filter wool
- Pond matrix in one baffle
- 2 stockings of crushed coral
- 2 or 3 stockings of zeolite
- 1 bag of crushed shell grit loose in one of the baffles
- I have a DIY denitrate filter with pond matrix and denitrate media within
- I have a DIY fluidised bed filter with pool filter sand (same as substrate...)

I am under the impression that the zeolite is reducing the hardness but also believe that it is helping to reduce the nitrates and therefore would like to keep it. Would I need to simply add more buffers to the tank to counter its effects?

Few questions:

What is the ideal GH & KH for frontosa?

If I replace the pool filter sand from the fluidised bed filter with all crushed shell grit would it help to improve the GH and KH?

Are there any other suggestions for raising the GH & KH? ...I'd rather not play around with bicarb soda and the like. I would prefer a solution that doesn't require adjusting regularly. I wouldn't think it is good for the fish if the readings are constantly up and down.

I would also prefer not to use commercial buffers if possible.

What is everyones GH & KH conditions like?

Thanks guys

Cheers

Joel

[dazzman]

Have you considered using crushed coral sand as substrate instead Joel?

[Joel]

Hi Dazzman,

I did consider when I started the tank but I have used some of the more fine crushed coral in the past and believe it was causing grief for different species of fish when they were breeding. Sometimes when I would strip a fish I would also pull out coral pieces which I think were damaging the eggs...

I'm not sure if frontosa would try to pick up the larger pieces - that might be an option.

Has anyone had success with shell grit or crushed oyster shells or similar before?

Is there way to raise GH or KH without the use of commercial buffers?

I would place them in the sump or FBF rather than the tank.

Thanks

Joel

[Ged]

The pH, gH and kH could all be a bit higher.

The lake's water chemistry varies due the vast size and other factors that impact on the chemistry. The range is generally accepted as

pH 8.8 to 9.3

gH:15 to 25 or 270 to 450ppm

kH:10 to 15 or 180 to 260ppm

Whilst buffering using a commercially available or home made Rift Buffer Additive is one method the use of substrate, rock work and bags of shell grit or oysters in the sump.

A great alternative to crush coral sand in the tank is to use crushed marble as a substrate. The addition of Texas Holey Rock will also give you the desired outcome.

[Ged]

Joel you can get marble chips of various grades from the following;

Mini-Crete Concrete

17 Chapel Street, Roselands NSW 2196

Phone: 02 9740 5722

[Joel]

Thanks for the info Ged.

I will give the shell grit a go I think.

See how I go over a few months.

Thanks

Cheers

Joel

[Joel]

Since I last posted I have changed my FBF media to a 0.5mm crushed coral.

I did try the shell grit but found it wasn't turning over as well as I'd hoped.

I did a some tests over a few weeks as follows:

Oct 26 - First test as shown in initial post above

pH = 8.0
NO3- = 10mg/L
GH = 140mg/L
KH = 40mg/L

Nov 2 - Replaced the FBF media with 0.5mm crushed coral

Nov 9 - Added a few small pieces of texas Holey Rock

Nov 23 - Test before two-week water change.

- pH = 8.0
- NO3- = 10mg/L
- GH = 120mg/L
- KH = 80mg/L

Nov 26 - Test a few days after previous test (I picked up an API GH/KH test kit and decided not to wait a few weeks for the next test)

GH = 11 or 196.9ppm

KH = 8 or 143.2ppm

Dec 7 - Test before two-week water change

pH = 8.2

GH = 13

KH = 8

It's kind of difficult to see as the units of measure changed over the time but the GH and KH has been raised.

It's still a little short of the range that Ged has posted above but I think this is maybe as high as I can get it before adding commercial buffers.

With the Holey rock, I have been told that it may raise the KH briefly but after it settles in and it gets covered in waste, bacteria and algae it really doesn't do a whole lot for the aquarium.

Up until Nov 26 I had no idea that we could get 0.5mm crushed coral! I thought 1mm was the minimum size...

It would be an improvement as a substrate than the 1mm stuff I had previously used for my breeding colonies. Not sure if it would cause the same nuisance when breeding.

Anyone have any other ideas for raising the hardness?

Cheers

Joel