cell

I'm asking a general question, and kindly awaits general answers, omitting voluntarily my tank's parameters:

I had an algae problem not long ago, mostly long brown hair algae.
I wasn't injecting CO2 at the time in my planted tank. When I did inject (DIY) CO2 (I was turning it off during the night). The hair algae was then growing at a slower rate and even turned red (or grew red I don't know..).

Lately, I forgot to turn off the co2 at night and noticed hair algae was decreasing in amount .


Now, I don't know if leaving the CO2 turned on all the time is the way to go, thinking long term (for the fishes/shrimps)..?

I do have low light plants (cladophora, anubias nana, java moss..) are they able to balance CO2 and O2 during the night (lights comes from a distant room)?

BenBOMB

You have to find out how much time your plants spend using CO2 during the day, and then start releasing O2 and gassing off their CO2.

I also had a very very bad case of green hair algae, it totally took over my tank. After changing the light cycle from 10hours to 7hours and adding liquid ferts 2-3 times a week, I noticed that my algae problem completely stop for the most part. Just learning the lighting cycle of your plants will really help you in defeating algae.

I have diy CO2 aswell and just leave it in 24/7, if I had a choice I would just turn it off at night but cannot without just gassing it off. Also I think the only light the the plants will really take effect from other then the one right above them is sunlight, other lights are normally not powerful enough. And the CO2 during the night is fine for the fish, they don't perfer it and actually would like it better if you ran an Air pump at night to push that co2 out, then don't run it during the day to let the plants recieve the co2.

Also when your plants pearl that means that they have gotten more then enough CO2 and are starting to release O2, knowing when your plants pearl is also a good thing to know, mine pearl around 7pm to 8pm when my lights turn on at 3pm and off at 10pm.

Just those few things will help your plants in the long run for sure.

pkeeler

It would be very hard to overdose co2 with a diy setup. Sounds like leaving it on 24/7, brought the co2 in solution up to a level that allowed the plants to out compete the algae. If you are worried about co2 poisoning, get a drop checker. If you want to turn off the co2 at night, then reduce your lighting.

surpera1

man - my diy co2 puts out big time - i'm looking to upgrade though - i run an airstone at night

rhodophyta

I did some reading on photosynthesis and found out that contrary to popular wisdom, all vascular plants absorb CO2 at night and that some plants including many desert plants, bromeliads and orchids only absorb CO2 at night and don't during the day when it is warmer and would take more of an energy investment. Since most or all of the aquatic plants we keep absorb CO2 24/7, it seems logical to supply it that way.

What I read explained there are two steps in photosynthesis. The first uses light to obtain energy, sort of like charging a hydrogen fuel cell, producing oxygen as a waste product. The second step uses that stored energy and the CO2 in the plant's tissue to create sugars, does not need light and goes on 24/7 even in plants that don't absorb CO2 in the day, relying on the CO2 absorbed the previous night. It would seem like if there were any time to stop injecting CO2, it would be for a while during the light period when the vascular plants might have an advantage over algae.

Enviroplasticity

To clarify on this subject, Cacti and succulents fix CO2 at night because their stomata are closed during the day to prevent dehydration due to the high temperatures which cuts off air curculation entirely. If I understand correctly, these plants still perform photosynthesis during the day, only instead of using co2 from the air, they use it from stored chemicals in their leaves from the night before. Knowing that aquatic plants will not close their stomata while submerged, I believe leaving co2 on at night does not make a difference to a plant's growth rate. However, I could be wrong about their growth rate for other, undiscussed reasons.

rhodophyta

Enviro, not an easy subject to clarify. There are two kinds or stages of photosynthesis. Light and water enable the first kind with light providing the energy to break apart water molecules and store that energy inside the plant. The other kind requires that stored energy and carbon dioxide. The plant's energy stores convert CO2 into sugars, which is a more useful to the plant way to store and transfer energy to where the plant needs it. So plants produce oxygen during the daylight photosynthetic hours, and all the time absorb CO2 (either from the habitat or stored CO2) in order to produce sugars.

ErioLover

Hmmm... very interesting.

I propose an experiment. 2 tanks the same size without filtration. One planted one without.

A accurate co2 test to find the initial co2. Wait overnight and retest to find if there is any significant difference. Then repeat 3 times to make sure it is backed up by the p value.

So who wants to volunteer?

rhodophyta

I'm not sure what Erio's experiment is intended to test. Whether the biology textbooks are right? Maybe they aren't or don't apply but I think a more interesting test would be to provide CO2 during the dark time and then see what the effects are on aquarium plant pearling and algal growth when it is shut off for a longer and longer time during the light period on an established plant tank with some algae problems.

ErioLover

My experiement is to see if the amount of co2 absorbed by our aquatic plants is significant enough so that we should leave on the co2 at night.

This way we can get some definate proof about if plants use co2 at night and if that is the cause behind inhibiting the growth of algae. Instead of argueing on this thread. Ofcourse you can always go back to reading your biology text book.

Right now I am testing if plants have a biological clock that is effected by our timing of when to turn on the lights. Thats is why I said at night, incase if there is a cycle and that would trigger the best response.

So far in my inintial results, it seems it does have a cycle and there is a timeing about when to fert and when to turn on co2 to maximize results. I'll report back when I get some solid proof.