CO2 questions?

[troutmaster]

Well I managed to get my Discus back into shape. After dealing with Disus gut rot disease. But now I have some other issues with Algae. I checked Phosphates(<0.5 ppm) Nitrates(5 ppm) Ammonia(1.0ppm.) Did a water change, added cycle and put in some Zeolite. I hope to get a handle on this algae problem as it was growing at a super fast rate. Like I could see it growing by the hour. I do have java fern, onion bulbs and hygrophilia in the tank. Hygro is doing pretty good, onion bulb not bad but fern has no new growth. My lighting in my 90 gal works out to about 1.2 watts/gal.- temp at 30C. When I had africans in the tank the fern would grow like crazy with little or no fert. and no CO2. I tried CO2 with the yeast method but stopped when I came home one day and found my fish gasping for air. I would like to try CO2 again as I did see an improvement in my plants with it. My question is how can you control the amount of CO2 with yeast/sugar method. Also won't the reduction in ph cause a problem at water changes as adding new water will cuase fluctuations. I think my ph dropped to 6.5 when I last tried CO2. I have been reading that unless you have at least 3 watts/gal that CO2 is not worth the effort, but I think it is as long as I don't kill my fish. I would hope that with CO2 my plants would be able to out compete algae for nutients. Any thoughts? Thanks. At this time I am triing to figure out what is going on with my nitrogen cycle. Never had this problem even when my tank was over stocked. I have increased my water changes from once to twice a week. THis includes vacuuming. NOT SURE WHAT THE HELL IS GOING ON NOW?

Edited January 15, 2006 by troutmaster

[Tanker]

Well... maybe I missed something but the lack of O2 could be related to the higher temp you are running... maybe some O2 injection/waterfall action is required. Plants need O2 just like fish do, and it sounds like you may only have enough in there for one of them. What is your filter method?

If you up the CO2, then you'll up the O2 byproduct during the day, but overnight the plants will consume O2 rather than produce it... and that can starve the fish if there isn't enough to go around (and slow/stunt the growth of the plants, too). With a tank at 86, you'll need a bit more than the 'average' O2, as well, as higher temps reduce the natural O2 exchange.

That's my two cents, not the 'whole' answer, but it may help. Are those plants 'happy' at those temps, as well?

[troutmaster]

30 degrees is my current temp. I use an air stone and use the spray bar off my 1 of 2 filstar's to mix air with the water at the top of the tank. The problem I had with my africans was when the water was at 76 F that is what I am getting at.How do add CO2 with higher temp with out killing fish. I am sure you probably manage it with CO2 using compressed gas as it would be easier to control. Not sure if I could do it with yeast method as control is harder. How do you measure O2 content in the water? I know how to measure CO2.

[jvision]

You don't have enough plants in there. And, with your light level, I wouldn't add CO2, either. Yes, it will help the plants, but with your stocking level, they won't produce enough O2 during the day to keep things in ballance overnight.

Try dosing some Seachem Flourish Excel, as per instructions on the bottle. It's a lot easier to control than DIY CO2, and you don't have to worry about asfixiating your fish overnight.

All plants will like it.

If you can, add a bunch more plants. And if you want to use CO2, up the lighting to at least 2 wpg. Try to keep the CO2 as constant as possible.

I bubble mine into a powerhead that is hooked to the same timer as the lights. During the day, the CO2 is misted into the tank, and at night, it just bubbles out w/o dissolving. Keeps everyone happy

[Milan]

Where does the ammonia come from? 1.0 ppm is very high for cycled tanks. This may be your reason why the fish are gasping for air, not CO2, and definitely the cause of your algae problems ...

In established (cycled) tanks, you get ammonia only if you overstocked it, the filter is clogged (next to no flow), or you somehow killed the beneficial bacteria (ie changed or washed all filter media at once)...

Edited January 18, 2006 by Milan

[Garhan]

What is your KH value ? As without that a 6.5 Ph doesnt mean anything as we can not determine the ppm in your tank for the C02 levels. There are several safe number that can be reached here provided the you do not exceed 30 ppm of Co2. If you look at a C02 chart it gives you values in a relationship between Ph and KH to determine C02 levels in your tank. Find one based on your base water KH and adjust the C02 flow into your tank to achieve the desired and appropriate Ph level to give you the right amount of C02 levels in your tank. Dont start messing with KH or GH if you do not need to. I would also remove the zeolite as it will absorb most of the ferts you add. Again here you would not be able to get true ppm readings on your N03 and P04 levels let alone K ratio to your nitrate would be out of wack. Discus after treatment can be comfortably be kept at 84 f or even less like at 74-78 F, which is still warm for most plants, but both the plants and fish are able to do well at this temperature. Of course over time some plants will adapt to a higher temperature, but they will struggle at that deperature and I wouldnt expect any rapid growth.

As for the lighting anything over 2 watts per gallon with 4400-6500 K ability is acceptable for good growth on most plants depending on the tank depth.

C02 input in my opinion should be added on any heavily planted tank regardless of the light levels within reason of course.

Garhan