increasing co2 as plants grow

[rockhoe14er]

As plants grow and a planted tank fills in more and carbon dioxide is used more and more by plants, will a drop checker show this decrease in co2 levels? For example my co2 levels were doing really well for the last month but yesterday i noticed my drop checker was a darker green than what it usually is.

Is this because my plants are using up more co2?

or is a month of growth too fast to see a difference in co2 uptake and the lower levels of co2 are from other reasons (maybe too much surface agitation)?

 

[Hallen]

The checker gives you an indication for that spot since Co2 isn't spread evenly throughout the tank. It can differ due to circulation (more plants = less circulation), and ofcourse more uptake from plants is very much possible as a cause since more Co2 is used so levels are lower in general.

I'd say move around the checker a bit and check if you have any deadspots where the circulation doesn't reach. You can also use one of those liquid filter solutions wich cloud the tank. You might have to redirect or increase the flow of current.

Personally I'd up the Co2 before checking for deadspots, just to be sure you're not limiting Co2. Do keep a close eye on the fish tho for gasping etc. Keep in mind that these checkers are an aid and only give a decent indication. Your own eyes and comonsense are still one of the most valuable assests in keeping aquaria.

 

[rockhoe14er]

yeah i move the drop checker around every couple of days to make sure the levels of co2 are constant. I have a ton of flow in my tank so i would image i have few dead spots. I have a 290 rated canister filter and a maxi 900 using the co2 mist method modification. It just struck me as odd that my co2 levels could drop in less than a month with everything else being the same. I upped my bps to 2 from 1.5.

 

[Wet]

I think you're on the right track. A month is a long time for plants to get going in a non-limiting tank. If you're doing EI right and assuming you aren't limiting growth, you should have a lot more hungry plants than you did a month ago. Do you?

Your drop checker tells you something is different. More importantly than the drop checker, how're the plants doing now? Do you have a day to increase CO2 and watch the fish for a while? If they're good, see if you can make some time later to increase CO2 again. If the plants look awesome but the drop checker says CO2 is low, check the drop checker, the solution, and the pH reagent. If your drop checker and the plants ever disagree, the safer bet is always the plant.

Also worth noting that many folks engineer tanks to run on relatively low CO2 (and plant uptake and light). It's entirely possible to have a healthy algae free tank with 10-15ppm CO2. These can be awesome relatively low-maintenance tanks. You can always adjust the drop checker to your new target as an indicator.

 

[rockhoe14er]

all the plants seem to be doing really well I dose EI. I just have shrimp in the tank atm but they don't seem to be acting too stressed out. However i'm not 100% sure what a stressed out rcs looks like.

how do you evaluate how the plants are doing? i don't have really any algae at the moment. They are green. I guess i'm not sure how to look at a plant and see if all their needs are being met.

 

[Hallen]

Really stressed out rcs are usually trying to be anywhere but inside the tank, that's basically the only way to know for sure if there's something wrong besides from them being dead. Quite active critters, always walking or darting around so not that easy to notice what their up to.

I compare plants to the ones in good looking tanks, besides that I look for spots or unusual colours on leaves, distance beteween internoides etc. A nice trick is to use stemplants as a timeline to see the effects of any changes you made. Let's say you up the Co2 and a week or two later the new part has more bushy and thick leaves in comparison to the old ones. Gives you an indication if the changes had any effect.

 

[rockhoe14er]

so does the distance increase between the inter-nodes increase or decrease as the co2 levels are higher?

 

[Hallen]

Well, you can use it as a rule of thumb at most. Generally speaking longer than normal internodes can be taken as a sign of low Co2. But of course there's more to it than just Co2 levels.

 

[Gerryd]

how do you evaluate how the plants are doing? i don't have really any algae at the moment. They are green. I guess i'm not sure how to look at a plant and see if all their needs are being met.

Hi,

A few things to look for:

1). Good leaf shape. Does it compare well with a published or described specimen?

2). Good color. Does it stay paler even as it ages? Many new leaves are paler, but as they mature they look the the older leaves.

3). No NEW algae anywhere.

4). Size of leaf. Does it seem like all your specimens are in miniature? Than perhaps not is all well

5). Internodal distance. Does it seem excessive? If you can see a lot of bare stem when looking at the plant, that is most likely not good.

6). Growth rate and mass. Do stems branch on their own? What about when pruned? Most will branch profusely. Do rhizomes (anubias, java, bolbitus) extend with new leaves? Do rosettes expand and send out runners?

7). Are they green when they should be red or some other color? Natural color will show through somewhat even if not in all it's glory. For instance, bronze wendti should not be green

These are all things that will help. With time and experience you will soon see these things.

Looking at others growth as benchmarks is always a good thing.

How does 'my' growth compare with others like Tom, Takashi, Oliver, Karen, and many others that publish regularly on the web? Many awesome photos out there for comparison.

 

[rockhoe14er]

wow great post. That helps a lot. I will try to see i if i can identify these signs. So far everything looks good and healthy but i guess only time will tell>

 

[barbarossa4122]

Yep, great post Gerryd. I am OK on all the seven signs you have mentioned.

 

[Tug]

Yea, just great.
[video=youtube;_dcn6vWLw-k]http://www.youtube.com/watch?v=_dcn6vWLw-k[/video]

 

[barbarossa4122]

Thanks ABC. Oh, and thanks Tug for another funny vid.