Wet/Dry good or bad for plants?

[JakeH]

If you think its too much agitation, try Flourish Excel as a carbon source instead of Co2. It doesn't gas out as easily.

 

[jcardona1]

yeah, as stated, if your not going for a high-tech co2-injected setup youll be fine. you could try Fluorish Excel but that would get silly expensive on a 315g tank

 

[JakeH]

yeah, as stated, if your not going for a high-tech co2-injected setup youll be fine. you could try Fluorish Excel but that would get silly expensive on a 315g tank

Wow...I missed that whole 315g part! Forget that unless you have a bunch of Seachem stock...

 

[londonloco]

My 120g has a sump and pressurized co2. No problem getting the drop checker lime green. It can be done...most people who say no sump have never had one.

 

[schaadrak]

My 120g has a sump and pressurized co2. No problem getting the drop checker lime green. It can be done...most people who say no sump have never had one.

Not saying it can't be done with a sump, just saying that running a W/D filter while simultaneously injecting CO2 into the water is counter-productive and an inefficient use of resources.

The primary function of a W/D filter is to gas out CO2 and increase O2 levels for the nitrifying bacteria colonized on the filter media so that they can convert ammonium into nitrate at a higher rate. Here are several reasons (some of which have already been stated) why that is counter-productive in these tanks:

1) You're gassing out what you just spent good money and effort to inject into the tank.

2) The high growth rates of plants in a high light, high CO2, highly fertlized tank removes nitrates, nitrites and ammonia much more quickly than a W/D filter ever will. So fast that N levels have to be replenished to keep plants healthy. So the bacteria (which you can't see) that your are try to culture are in direct competition for the same nutrients as the plants you are spending so much time, money and effort to look great.

3) As I stated earlier, high CO2 levels are quickly converted into high O2 levels by the high photosynthetic rates of the plants. Much higher than the surrounding atmosphere so that instead of increasing O2 levels, aerating the water actually decreases the O2 levels, which is completely counter-productive to the core function of the filter.

4) There are a multitude more surfaces for bacteria to colonize in a planted tank than a non-planted tank. Finer, richer, substrates are thicker in planted tanks and have much more surface area than plain gravel. Plants themselves harbor bacteria as well. As do all of the rocks and driftwood that seem to be more abundant in planted tanks

5) Bacteria in the main tank are exposed to a higher organic content for them to feed off of than the highly pre-filtered water that trickles through the filter media of a W/D chamber. So there is a much better environment for bacteria in the main tank than in the sump.

6) (this one's kind of a stretch, but I'm on a roll ) You will only have as much bacteria as you have nutrients available for them to feed on, so culturing them in a W/D may only really be decreasing the levels in the main tank.

So, sure you can achieve high CO2 levels in a tank that is run with a W/D filter. It's not unlike ordering a nice healthy salad to get fit and then smothering it in two scoops of ranch dressing, bacon, ham, cheese, and croutons. Good luck!