Yeah, that really helps. Thanks again, Scott. When I said "buffer" I meant "Discus buffer"; Seachem makes it. I've heard it's bad to use because it contains phosphates and throws off C02 chart/readings. The carbonate hardness in my tank is 4 degrees, because I added baking soda once, and I think it's been there ever since, and I keep crushed coral in my filter. With a 7.5 pH reading the C02 is between 3-5 ppm. Low! Am I going to have to add more C02? I didn't want to get a pressurized system for this tank; it's supposed to be my low-light tank. What other kinds of acids were you talking about? I don't want to experiment too much, though. This is my discus tank, and they come first. For this tank I use DIY yeast reactors for C02. If I add more yeast, will I get more C02? Adam -----Original Message----- From: aga-member-bounces@thekrib.com [mailto:aga-member-bounces@thekrib.com] On Behalf Of S. Hieber Sent: Tuesday, September 27, 2005 4:20 PM To: Aquatic Gardeners Association Member Chat Subject: Re: [AGA-Member] Low-light tanks & CO2 A buffer will raise you KH, not lower it. The easiest way to lower the pH is to add a mild acid. Adding CO2 will do this since a portion of it in water forms carbonic acid. IF your tapwater is 7.5, you shouldn't have any problem getting the pH down to discus-target levels by adding more CO2. If your KH was 3 degrees, 30ppm of CO2 would drop you down to a pH of 6.5. So with tapwater of 7.5, and not adding other acids, CO2 should do the trick without ever getting to harmful levels. I would probably raise the KH a couple of degrees by adding some calcium carbonate or sodium bicarbonate with each water change. A little buffering will keep the pH a bit steadier. Even if you raise the KH up a couple of degrees, you can still get a nice 6.5 pH without overdosing on CO2. Adding CO2 doesn't require adding more light although the inverse is not necessarily true. YOu might find you need to add a littel more ferts or fish food -- but with discus, that is usually not a problem, given their ravenous appetites. ;-) hope that helps, sh --- Adam Michels <amichels@trafficleader.com> wrote: > > Hi, everybody. I joined AGA only a few weeks ago; I was > wondering why > everyone liked mosses so much until I received the new > quarterly! > Anyway, I'm confused about achieving equilibrium in my > low-light plant > tank, and I could really use your advice. > > Tank specs: > Tank: 75 gallon > Lighting: 4 28W T5 full-spectrum(2) and 6700K(2), 1 20W > fluorescent, 1 > 15W fluorescent > Filter: Fluval 304 > Substrate: 2/3 Flourite, 1/3 Eco-Complete > CO2: 2 Hagen Nutrafin DIY yeast reactors + 2 ladders > Heating: 2 250W Stealth > Set-up: 2 10lb. plus driftwood stumps > Plants: 1 large Aponogeton boivinarius, 2 Aponogeton > madagascarensis, 1 > Aponogeton crispus, several odd smaller Aponogetons, 12+ > Crypts, 1 large > Kleiner Bar Sword, 1 Echinodorus major, 1 Echinodorus > osiris, several > large Anubias barteri tied to driftwood, mid-sized > Anubias congensis, > nana, azfeli, frazeri, Sagitarria subulata, many > Sagittaria pusilla > (Dwarf Sags), many Echinodorus tenellus and some java > moss > Fish: Five 4-5" Discus, five Roseline Barbs (denisoni), 3 > spotted > headstanders, 1 gold nugget plec (small), 1 rubbernose > plec (small), 1 > pair killifish (Nothobranchius kafuensis) and 4 emerald > cories > Tap water: 7.5 pH, 1 dH(17.8 ppm) carbonate hardness > Tank temp: 81-82 degrees F > Additives: Kent Freshwater Plant liquid fert. every water > change, > crushed coral in the filter bed to raised KH and GH > Water Parameters: NH4=0, NO2=0, NO3=less than 12 ppm, pH > 7.5 before > turning off lights (haven't checked morning reading) > > I wish I had a picture. Things are fine other than I do a > lot of water > changes. But I want my plants to flourish, and the fish > to enjoy water > parameters similar to their natural habitat. The problem > lies in that I > can't get my pH down. I do so many water changes for the > discus that the > driftwood doesn't have a chance to release enough tannic > acid fast > enough, and I don't add enough C02 to lower the pH. > Should I buffer? I > want my pH under 7.0, for sure. > > Am I going about this correctly? I raised my discus in a > species tank, > bare-bottom, but they don't seem to mind the new > additions. The killis > look hilarious, but I don't have any where else to put > them! > Any suggestions would be greatly appreciated. > > _______________________________________________ > AGA-Member mailing list > AGA-Member@thekrib.com > http://lists.thekrib.com/mailman/listinfo/aga-member > * * * * * * * * * * * Coming Soon in November, the winners and all the other beautiful entries in the 6th Annual International Aquascaping Contest. Every continent is represented -- except Antarctica. Maybe next year Antarctica, too ;-) http://showcase.aquatic-gardeners.org _______________________________________________ AGA-Member mailing list AGA-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/aga-member _______________________________________________ AGA-Member mailing list AGA-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/aga-member