# Effects of excessive oxygenation from sponge filter on plants



## mattdocs12345 (Oct 13, 2014)

So I have a 10 gallon tank with sponge filter and Incant help to notice that the plants right next to the sponge filter don't seem to be doing as well as those on the other side of tank. I read somewhere that excessive O2 exchange with sponge filters can limit CO2 exchange. Can anybody else provided some input on this?


----------



## dannifluff (Jul 5, 2015)

I believe you're right mattdocs. The bubbles from the sponge filter will increase CO2 loss from the water. Generally, in high tech planted tanks where additional CO2 is added it is recommended to turn off aeration during the day and only have it on at night (when plants begin to respire, leading to increased CO2 in the water... depending on how much CO2 is added during the day this can lead to excessive CO2 overnight, endangering fish, hence the additional aeration overnight to keep the balance).

However, not really possible when the source is a sponge filter.

If you're not adding CO2, the best suggestion would just be to try switching up your tank a bit, to see if you can move your plants to an area where there is less surface water movement.


----------



## mattdocs12345 (Oct 13, 2014)

hmmm I will experiment a little bit. I will change the filter to internal one and see if my plants grow faster. I don't have CO2. I only use 11wats per gallon LED lights and fertilizer.


----------



## dannifluff (Jul 5, 2015)

With low tech tanks you don't need CO2, however before changing out the filter (just because it will be cycled and they generally are very good for Bettas) I'd just see if you can change the plants around a little to give the ones nearest the sponge filter some time in the lower movement part of the tank.

What plants do you have that are suffering? I find slow-growing plants like anubias are quite good to put around where I have my airstone, since it seems to bother them less.


----------



## mattdocs12345 (Oct 13, 2014)

Hornwort and Anarcharis. Both are turning more brown near the filter. Also Amazon frogbit doesn't seem to do well near the bubbles (leaves rot when exposed to excess moisture). 
I really don't have much space to move my plants because they pretty much overtook the tank. But I do see less growth near the sponge filter.
I'm going to take apart the sponge and place it inside of the aqua internal filters. They are small, provide more directional water flow.


----------



## dannifluff (Jul 5, 2015)

That sounds fine. I've never had any luck with amazon frogbit since my tanks are hooded. I like salvinia minima as an alternative, though.

I've also found hornwort and anacharis tend to do better floating or gently weighted rather than planted.

Hopefully an internal filter will improve things for you. If you have floating plants, they generally take care of the protein film from low water surface movement, so if you can reduce water surface movement down to next-to-nothing, it should help a lot.


----------



## jadaBlu (Feb 14, 2013)

Try moving the filter outlet below the surface and to another location to create less surface agitation unless you have fish that need lots of oxygen.


----------

