Lake Malawi Bio-tope frustration...

[greenmaji]

Ive been doing some research to do a lake malawi biotope.
I keep running into frustrating facts.. I cant have ph values as hi as I want with co2 level were I want them, the fish would not be able to handle the dKH levels needed.To buffer the water to higher than tap water levels you would think of using a carbonate based substrate like crushed coral but Im reading the planted tank basics right now and the author says to avoid them without really explaining why to avoid them. Im sure there is a good reason.. anyone know what that is? I would like to buffer the tank everywere possible and taking the substrate out of the loop is a biggy for me.. 8O

 

[malkore]

I have a friend who uses carib-sea's Cichlid substrate, and mixes it with eco-complete.

Crushed coral isn't for FW tanks, not as a substrate at least.

Baking soda will raise your Kh levels too.


You have yet to mention how much light you have on this tank. If you have low light, CO2 levels aren't even a concern.

 

[greenmaji]

FYI

I plan on having about 220 watts when I get the lights. Im planning on getting a CO2 system as well.

 

[greenmaji]

and with the carib-sea Cichlid substrate.. isnt it a carbonate based substate or was the advise just general advise.. I am aware that CC and sand are normaly not used for FW.. Im looking for what would be correct for lake Malawi.. it has alot of KH from being a rift in the earth..

 

[greenmaji]

My need to raise the dKH levels right now is in question.... Im looking at the peramiters of the lake right now on a biotope site and it says ideal levels would be 18 dKH and a ph of 8.1 ... that would only hold a CO2 level of about 4mg/l wich is not exceptable.. it says there range in hardness is 10-30dkh Im wondering what dKH level to ph to keep the tank at.. shooting for a 20 mg/l co2 level.. I realize that this is a matter of opinion....

 

[malkore]

Sit tight. I'm gonna bring in a peer who's somewhat of an expert on this setup. Give him a couple hours to reply.

 

[travis simonson]

Given a desired target level of 20 ppm CO2 and 18 dKH you will need to compromise and run your pH at 7.4. IME Africans can be easily acclimated to this pH level and show no ill effects whatsoever, as long as it is done gradually. In my case I slowly lowered the pH from about 8.0 to 7.2 (I only run my KH at 12-14 dKH) over the course of a month and the fish are in great shape and breeding like rabbits. Basically there's no way around the whole CO2/KH/pH relationship in an ARLC tank with plants unless you're willing to compromise on one of the three points

 

[greenmaji]

thank you travis.. or e-mails have helped me allot... I have a chart for the co2 levels that goes up to 18 dKH, and it says somewere around ph 7.45 for 20 mg/l wich would be 22 at 7.4 in other words your right on.. I was wondering If you had a math formula for this relationship or a chart that goes past were mine does? thanks again..

 

[travis simonson]

I've got the formula in an Excel spreadsheet somewhere on my system if I can find it. I think I actually got it from Malkore (you still have that man?) If all else fails you can download Chuck Gadd's Nutrient Calculator from the link below:

http://www.csd.net/~cgadd/download/aquacalc_setup.exe

This is bar-none the handiest planted aquarium tool out there, and it's free

 

[greenmaji]

that program rocks!... I did my first calculation.. this one is a little funny...
target CO2-20, dKH 30!!, PH-7.7... I think the plants would die, and the fish would get sick at that level!!! but at least I know what Im dealing with now! Thanks guys...

 

[travis simonson]

that program rocks!

Yes Chuck's calc never lies I'd be willing to bet that Africans might manage at an extreme KH like that, but I would never go that far just for CO2 because it would kill your plants Stick to manageable levels, learn to compromise, and make objective observations. With the kinds of plants you're planning on growing, I think you can easily get away with an 18 dKH. Even if not, your fish will still thank you for the hardness

 

[greenmaji]

to be honest with you I figure Ill be getting captive bred fish and just need to find out what they are already aclamated to and go from there.. I doubt the people or companies I would be getting the fish from will have the extremes of the wild in there tanks. I usually just get my fish aclimated to my tap water to be honest with you!..lol. I have a flood of questions about nutrients and the chemicals that ive read people put in there tanks to immulate this enviroment.. some of them are the same as plant nutrients if im not mistaking.. I dont think ive seen these questions on here but I will try to take a look..
later guys..
In other words you dont need to get me to compromise..Im really not that stubborn. though it might seem like you do..

 

[malkore]

Keep in mind, that formula can be off by up to 10%...however at our levels, you're talking about 2-3ppm of CO2, max...so nothing to worry about.

I do indeed have an Excel spreadsheet with Chuck's formula in it.
CO2 (in PPM) = 3 * KH * 10( 7-pH ) where KH is Carbonate Hardness in degrees

The hardest part is the '10 to the power of 7 minus the pH'....and then figuring out how to put that into Excel.
I'll post the exact formula I use in Excel..however I have it reading the pH and Kh values from 2 columns in the Excel file.

=3*L4*10^(7-K4) -where L4 is a floating reference to the column containing my Kh, and K4 is the column for pH

And here's a sample spreadsheet so you can see it in action: click here

 

[greenmaji]

you dont need to explain the forumula in any greater detail unless someone reading this needs it.. I understand it just fine..
CO2= 3KH * 10^( 7-PH)
good to know though..

 

[greenmaji]

my question about mixing carbonate materials into the substrate to buffer the ph has kind of been lost. I understand that your friend malkore is using something that I think has carbonate material in it.. Im not absolutely certain of it though. And how this is not advised, and not exactly explained why, by the article that is posted.. TIA

 

[travis simonson]

I use Eco-Complete Cichlid Sand (which is carbonate buffered) mixed roughly 50/50 with Eco-Complete Planted Tank Substrate. I didn't really set out to do it this way. I originally started this tank as an ARLC tank and used 100% Cichlid Sand, but I quickly decided that I wanted to try growing plants so, over the course of several months I gradually added EC Plant Substrate to help the plants out. The reason Cichlid Sand is not recommended for use with plants is that the roots of some plants can be damaged/burned by the high KH of the sand. The sand also buffers the water column's pH and KH and some believe this makes it much harder to grow plants. I can't say that I agree with that, however

 

[greenmaji]

from looking at your aquarium Im guessing that the theory needs a little more research! LOL.. can you say that you have seen any of this "damage/burning" on your plants roots.. have you examined the roots of your plants to see if they are having any problems with this?

 

[travis simonson]

I can't say I would really even know what to look for, but I have found several species of plants that just don't seem to do well in water with a KH of 14+: Ludwigia sp. 'Pantanal', Myriophyllum matogrossense 'Green', Nesaea sp. 'Red'. One thing I have noticed is slower growth in many species that are noted to prefer soft water. While they still seem to do well in hard water, their growth is noticeably slower.

All of this is just observational data and I can't say any of it is absolute fact, so take it as you will

 

[greenmaji]

travis..
I can understand that.. I was just wondering if you saw something abnormal. It sounds like the plants that dont do well was to be expected, since they prefer soft water. Im glad you are filling me in on the plants not to get for this setup.. I think it will be much more simple than yours.. as far as diversity of types of plants.

Im going to finally ask the question.. What are you using to take the pictures of your tank. Your not the only member I would like to ask that question to by the way.. every picture seems to have been taken by a professional photographer.. I think im going to ask this one in the general discussion area as well.

 

[travis simonson]

LOL - don't think I'm a professional by any means. For every good pic I get there are probably fifty that I throw out. That's the best part of digital photography - no wasted film I use a Sony DSC-P92 5.1 megapixel model which I'm not even sure they make any more. It takes good all-around photos although I'd like to get my hands on one of the new models with the Zeiss aspherical lens and a little higher resolution