Java Fern/Moss and high tech

Nubster

I was reading that high tech setups can actually slow or stop the growth of Java Moss and Java ferns. I just changed my tank to mostly these plants with a few crypts so now I am wondering if I'd be better to go back to low tech. These plants have been in my high tech tank for some time, haven't noticed anything bad with them but growth hasn't really been there either. I am medium light, PPS Pro ferts, pressurized CO2, maybe 2-3 bps, drop checker stays on the darker side of green. It's an invert tank so I don't want to get too crazy with the CO2 but I would love to see some better growth, especially out of the ferns.

DKRST

Had not come across that info (just started using pressurized CO2 in one tank), but perhaps it has to do with the acidification of the water by the CO2 (CO2+H2O =H2CO3 carbonic acid)? If that's so, a "GH Booster", basically a pH buffer, might be helpful, but I'd use that only if you start having issues. I'd try the plants and CO2 first and see what happens. I can't think of a photosynthesis-related reason that CO2 would hurt those plants.

Nubster

They are staying healthy, just don't seem to be growing much. I've had the needle leaf the longest and it's been in my tank a couple months maybe. I would just love to see it explode so I don't have to buy more to fill in my tank...lol

DKRST

There are certain plants that simply don't do any better no matter what the CO2 level. Anubias doesn't seem to grow faster with CO2, perhaps that's the issue here as well. Mosses and ferns are on the "primitive" side for plants.

Nubster

Yeah, the Anubias in my tank has been there since October last year, other than a few new leaves it hasn't done squat...lol...I just pulled it since it really was just taking up space.

Byron

Java Fern, Java Moss, Anubias are all low light requirement plants. All low light plants have slow growth, relatively speaking. Growth is directly related to light. Plants that grow in shade tend to grow more slowly than those that require direct sun.

Increasing the light and nutrients in balance might have some impact on growth, I've never tried it, but i suspect it would be minimal. It would still be limited by the plant's natural tendancy to grow slowly. As for CO2/light actually inhibiting growth, I've no evidence; I do know that Java Fern does not do as well under direct light.

I would not waste CO2 and high nutrients on low light plants. If the CO2 is needed for other reasons, such as acidifying the water, that is different. But these plants will tend to grow better (by which I mean naturally) in more natural systems.

Byron.

Quantum

got this online, as best as I can tell it is from a University of Hawaii botany or ecology course



At some point the rate of photosynthesis levels off no matter how much light is present (saturation point), for low light plants this point occurs at lower light intensity. Not shown on the graph is photo inhibition, when increased irradiance results in lower rates of photosynthesis.

Nubster

I'm not sure really how much light I have. I'd say medium since the reflectors on the fixtures pretty much suck. I do know that other plants like my crypts and swords grew like CRAZY. The crypts are a lower light plant however the swords are not.

Byron

Crypts are sometimes referred to as "low light" but this is a bit misleading, since they are quite different from the earlier mentioned plants. Crypts occur as amphibious plants and some species are in direct sun. The nice thing is that most all species will manage well in low light, which is why they are frequently considered in that context. But given brighter light, they can exhibit different growth. Most species change their growth according to the light intensity, and this is actually common with many substrate-rooted aquarium plants.

Before you start changing things, remember that all this is a balance. Light and nutrients must be in a specific balance, so if you start messing with light you're only looking at one component. Increasing or decreasing one aspect does not mean better, unless that specific aspect was out to begin with. If the CO2 is to be discontinued, which was my earlier intention, then the light may be sufficient or it may need reducing.