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CO2 for Dummies - A Practical Perspective

CO2 for Dummies - A Practical Perspective

Tips by Dou Mok, Felix Smart Ambassador 

If you're starting a freshwater planted tank, you will inevitably run into the question - do I need CO2 to grow plants? The short answer is no - you actually don't need CO2 to grow plants. The long answer is not for dummies - so I'll leave that to the experts* to discuss. However... "no" doesn't mean that all plants can't benefit from CO2 injection. So, what do you really need to know?

* https://www.advancedplantedtank.com/blogs/choosing-co2-why

Buy things once, right - not twice.

There is no question that you should consider buying and setting up a CO2 system if you are serious about growing plants underwater. There are various options out there, but the one I recommend is the option that involves a CO2 Cylinder and a Regulator with Solenoid. Do your research and buy products from reputable brands so that you can focus your attention on your tank and plants. Injecting CO2 is something you will want to put on a schedule and automate so that you don't have to manually turn on and off (Use the FelixSmart's Range feature!).

Take things slowly at your own pace.

It might be tempting to add a lot of CO2 in your tank at first because you want your plants to grow fast, but adding CO2 does not come without it's own complexities. With any new element that you add into your tank, you should take things slowly so that you can observe the changes. Start with 1 bubble per second and see what happens after a week. If you have many plants, consider starting with 2. Make sure that your CO2 bubbles are being spread all throughout your tank - this might mean moving your CO2 diffuser underneath your outflow! If your tank is one that develops an oily film on the surface, add a skimmer and set that on a timer (use the Felix Smart's Range feature!). If you have fish, they will appreciate you giving them some time to get used to the CO2.

"The Water Tests" vs. "The Eye Test"

How does one find out if one's tank has enough CO2? You can either test your water parameters (pH/kH) or do an eye test. The eye test is about confirming that your plants are growing by observing whether you see pearling (photosynthesis) or not. George Farmer* describes this best - it happens when plants have the food they need to grow so well that they start to form visible bubbles of oxygen on their leaves. You should be able to observe this happening within 2 hours of your lights turning on if you inject CO2.

If you really want to get into this more, I'll leave you with some verbiage from Tom Barr**: "Adding CO2 increases photosynthesis 10-20X normal rates without adding it, thus the O2 is produced at a much higher rate. This leads to more pearling due to O2 production by the plants. Oxygen is pretty insoluble in water to begin with, CO2 is not. Try and get 50 ppm of O2 into your tank's water sometime. Water is equilibrated with air at 100%(say 7 ppm at 28C), but it's so "saturated" that O2 forms into bubbles and pearls away."

The water test is not for dummies so if you're ready to challenge yourself, here is some advice from Dennis Wong***, author of "Advanced Planted Tank": "As a very general guide, if you have KH values between 1 - 10 dKH, aim for a 1 point relative pH dropfrom the point when CO2 injection is not yet turned on to the time after it has been turned on and CO2 has risen to a high, stable equilibrium point."

If you have a Felix Smart, you can easily monitor the pH through the App as a rough way to gauge your CO2 levels. Practical.

* https://www.youtube.com/channel/UC210QPUiYoCjm9IEuu5SHLQ
** https://barrreport.com/
*** https://www.advancedplantedtank.com/blogs/choosing-co2-why/the-wrong-way-to-read-the-ph-kh-chart

Remember, every tank is different just like we are as humans. The right answer is the one that works for you and your plants - don't feel pressured into doing something that you don't feel comfortable with (or at least do your research!).



Driftwood in Aquariums - What You Should Know

Driftwood in Aquariums - What You Should Know
A favorite aquascaping material, driftwood has been used by aquarists since the dawn of fish keeping to create beautiful and natural aquascapes within our aquariums. There are a wide variety of woods available, all with unique shapes, colors and textures, making it easy to find a type of driftwood to match your taste. Driftwood, despite being a wonderful decor option, does have a few properties you will want to consider before plunging a choice piece in your aquarium.



Driftwood, like most plant material, contains tannins. So unless you are trying to achieve a blackwater biotope, you will probably want to mitigate as much of the tannins as you can. Pre-soaking driftwood in hot water for a few hours will help remove a lot of tannins before you put the wood into your aquarium. You can repeat the process several times until the wood has lost the majority of its tannins. If you still end up with some yellow coloration in your aquarium even after you've pre-soaked your wood, a small amount of carbon in your filter can remove the coloration.


Wood Floats

Until it becomes waterlogged, most driftwood will want to float, although some types of wood are denser than others and may naturally want to sink. When aquascaping with wood, it can be beneficial to mount the wood to a piece of slate, or other rock, to help keep it in place while it slowly absorbs water and naturally weighs itself down. Alternatively, pre-soaking the wood until it sinks is a great way to make sure the aquascape you worked hard to achieve does not float away as you fill the aquarium!


Breaking Down

Wood is organic and that means it will break down over time. How quickly it breaks down will depend on a number of factors, but on average, most driftwood will begin to show signs of deterioration as early as 2 years after being submerged and may need replacing after roughly 5 years. As the wood begins to deteriorate, the outside of the wood will start to feel soft and fall away in the form of fluffy, muddy debris. This debris can build up on the substrate of the aquarium and resemble piles of fish waste. It will often be sucked up by the filter and can clog mechanical media with a dark brown mud. If the rate of deterioration is making aquarium and filter maintenance difficult, it is likely time to replace the driftwood in the tank. This might seem unfortunate, but it gives you the opportunity to re-scape your aquarium and try something new, be it another driftwood showpiece, or something more permanent like dragon stone!


With these considerations in mind, working with driftwood to create beautiful aquascapes and biotopes can be a fun and rewarding process!

3 Easy Steps for Crystal Clear Water

3 Easy Steps for Crystal Clear Water

There is nothing quite like having crystal clear water in your aquarium, but achieving crystal clear water is not always easy. Particulates like dust and debris, tannins from driftwood and suspended algae can make your water look foggy, discolored and dirty overall. The good news is, there are 3 simple steps you can take to help remove any unwanteds from your water and achieve that stunning clarity all aquarists strive for!

STEP 1 - Activated Carbon

Activated Carbon is a chemical media that when added to your filter, or aquarium directly in a media bag, will absorb a wide range of chemicals including tannins, and other substances that can cause discoloration to your water. If your water happens to be a little smelly, activated carbon is going to help remove that as well.


STEP 2 - Fine Filtration

Poly pads, filter floss and felt pad media with a small micron rating placed inside your filter are some of the best options for removing small particulates like dust, mulm and even suspended algae from the water column. Most filters will have branded options for fine filtration, but best results may come from a specialized cut-to-fit micron pad with a rating of 100 microns or less. Keep in mind that this filter media should be used for maintenance only and not all the time since it will bog up quickly with dirt and debris. 24 to 48 hours is usually all it takes to get the job done.


STEP 3 - Water Clarifier (Flocculant)

The last step that will really boost the results of step 2 is the addition of a water clarifier. In essence, a water clarifier is a liquid additive that acts as a flocculant to bind all of the tiny particles in the aquarium into larger clumps, making it much easier for your fine filtration to pull out even the tiniest of particulates. This is where we most often see the water really clear up to the point where it looks like our fish are floating on air!


Following these 3 steps has a proven track record of excellent results and can be the secret weapon of any aquarium owner looking to achieve that highly sought after ultra-clear water.