CO2 question for planted tank

[sidra]

I have a 75 gallon planted tank with six discus, two rams and 5 tetras. GH4, KH3, PH 6.5 (all with no adjustments). Phospate .25. My question is about the CO2. It was steady at 8 for a while but it has now dropped to 4. If it continues to drop what else can I try before getting a CO2 system. Will just cutting back the hours of lighting help? Right now tank lights are on 7:30 am to 9 am. Then daylight (not a lot of natural light in the room) all day and tank lights back on 4 pm to 10 pm.

There are eight plants...anubias, ludwigia, amazon swords...

I have a small amount of brown algae growing on the anubias and that I have to wipe from the glass but it's lessening all the time.

Any input is appreciated.

Thanks,
Kristen

[imatrout]

Do you inject pressurized CO2 into your tank? Go here to learn all about CO2. CO2 is the key to success in a planted tank!

http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

[imatrout]

Also, that brown algea on your anubias will stay off forever if you get a bunch of Nerite snails. They are the BEST! They do not reproduce so you'll have to buy the quantity you want. Typically 1 per 2.5 gallons will do. You can get them at www.azgardens.com they are a GREAT investment!

[Doug A]

Kristen

Brown algae is usually cause from lack of light. You should have the lights on for about 10-12 hours a day. Try keeping the lights on for a steady 10-12 hrs.(not on for a couple then off then on again.) This should help with the brown algae if proper lighting is used.

Is the tank heavily planted or just a few plants?
How much and type of lighting?

Doug

[sidra]

Thanks for the replies.

No, I'm NOT injecting CO2. I'm hoping not to, but will if it's necessary.

I could try leaving the lights on longer to get rid of the algae, but will that make my CO2 go down even further (based on plants using it more when it's light)? Sorry if I seem dense, but I'm just learning all this stuff.

I definitely want to get some of those nerite snails.

The tank has eight plants in it right now and I just bought three more after I soak them in alum overnight.

Uh-Oh...I just looked at my lighting..it's the standard light that came with the Oceanic 75. It's a GE Aquaray and only 40 watts :( . I've been wanting to replace the bulb anyway, but get confused about what to get. Can someone tell me exactly what bulb would be good for a 75 gallon planted discus tank? I don't want it so bright it makes the fish unhappy.

BTW, my discus thank you for that extra snack they got...when I opened up the canopy to look at the light they begged so they got some flakes!

Kristen

[RAWesolowski]

Kristen,

Hopefully, you have low light plants that like warm water in your discus tank.

Generally, we talk about "low" light tanks as having 1.5 watts per gallon (wpg) or less, medium light tanks go up to 2.5 wpg with "high" light tanks above that range.

Tropica has a great website for researching compatible plants at www.tropica.com. In addition to a two part article on planted discus tanks, the coolest thing is the ADVANCED SEARCH BUTTON in the upper right hand corner of the home page. The feature allows you to plug in your tank size and parameters to find plants that work for you!

Oh, most people like bulbs in the range of 5500K to 6500K for plants as the spectrum length works well. However, The "K" rating will affect how your fish will look in the aquarium so you might want to take a look at the Hagen brochure on light impact.

Note: Do your conversions to metric and centigrade before going to the site!

[sidra]

Thanks, Bob. I am definitely going to get a new bulb. My plants so far are doing really well but I'm sure will do even better with a higher wattage bulb.

I will check out that site, thanks.

Kristen

[diablocanine]

I have a 75 gallon planted tank with six discus, two rams and 5 tetras. GH4, KH3, PH 6.5 (all with no adjustments). Phospate .25. My question is about the CO2. It was steady at 8 for a while but it has now dropped to 4. If it continues to drop what else can I try before getting a CO2 system. Will just cutting back the hours of lighting help? Right now tank lights are on 7:30 am to 9 am. Then daylight (not a lot of natural light in the room) all day and tank lights back on 4 pm to 10 pm.

There are eight plants...anubias, ludwigia, amazon swords...

I have a small amount of brown algae growing on the anubias and that I have to wipe from the glass but it's lessening all the time.

Any input is appreciated.

Thanks,
Kristen

I do not understand the part about the CO2 dropping from 8 to 4. What does this mean? I am familiar with measuring CO2 by ppm, using kh and ph to determine CO2 saturation. For example a ph of 6.5 with a kh of 3 will give you a CO2 level of 28.46ppm when adding supplemental CO2.

The plants you listed in your post do not need high light but they are root feeders that need a good substrate or supplements. When purchasing bulbs do not go over 10,000 kelvin. 6700k, 6500k, 9600k, 10.000k; they are a matter of preference, they all will work with a planted tank. I use 10k and 6700k in my tanks. I have 384 watts of 10,000k beaming down on discus in my planted tank, they will adapt. If you are happy with a low light tank you can add flourish excel. Along with the previously recommended site (http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm) I would reccomend also reading the info contained here:
http://www.rexgrigg.com/

[Alight]

If you are using a CO2 test kit to measure your CO2 levels, then you really don't know the CO2 level.

I don't know how you could have more than 5 ppm CO2 in your tank the way you describe it. Without adding CO2 with either DIY or a pressurized system, unless you had more fish tha you say, or something rotting, or very little aeration, it is unlikely you have had 8 ppm CO2 in your tank.

On the other hand, with the lighting you have, any CO2 addition would be a waste, anyway. The plants won't be able to use it.

You cannot buy a higher wattage bulb for a normal fluorescent fixture. You will need to buy a new lighting system if you want to go to moderate or high lighting. Amazon Swords and ludwiga need at least moderate lighting to do well. They can struggle along with less though. Anubias can do OK with low lighting, but algae could be a problem on them, since they are very slow growing with low light.

Discus do fine (mine seem to enjoy it) with 3-4 watts per gallon.

Much, much to learn (we're all still learning--Even Tom Bar) with planted tanks.

[sidra]

I have exactly the number of fish I said I have and the tank has only been running for 6 weeks (four weeks planted). I use the Red Sea CO2 test. I've tested once a week and watched it go down from 8 to 4. (followed the instructions exactly). Also there are two four inch air stones running in the tank.

I figured I'd have to buy more than just the bulb...that wouldv'e been too easy. LOL

Kristen