Location of diffuser in tank

[Jaffar]

All the while I thought you should place the CO2 diffuser as far as possible from the input of the filter so that the CO2 has sufficient time to dissolve in the water.

However, a friend told me that I could also put the diffuser closer to the input of the filter (canister filiter) so that the excess CO2 which is not dissolved by the diffuser could be sucked into the filter. The filter will ensure that the excess CO2 would be more thoroughly dissolved within the filter before it outputs.

It may be a naive question but like to hear from the many experts in this forum. Many thanks

[ongart chareonpong]

The whole concept is to make sure that the dissolved CO2, in your case by the diffuser, get used up by the plants as much & as long as possible before the left over is sucked out by the filter. So if we agree on this concept then you can easily answer your question yourself, right ?

For my 5 ft tank, where the filtered water input is on the left of the tank & the output to filter is on opposite side, the diffuser is closely located to the input outlet.

Hope this helps.

[Aquaculture]

In a way, your friend is correct but by placing the diffuser as close to the filter's inlet, what are the percentage of CO2 being distributed to your plants... rather minimum.

I would suggest to distance the diffuser and the inlet to opposite ends of your tank. This would give CO2 more time to disolve before being recycled back into your filter and a chance for your plants breath the intended CO2...

[uklau]

I would put it at the deepest part of the tank with water flowing around this area to distribute the mist.

[wasabi8888]

I have a Juwel tank and I placed my diffuser into the filter box where the water is being sucked in.

I think there will be many discussions on this and I was pretty confused myself. End of the day, look at the condition of the plants and test it out. You will probably find the answer yourself.. My 2 cents worth

[Shadow]

I tried misting before, though many people said it improve plant grow but I didn't see any different. Maybe because I base on my own observation instead of using ruller and measure how long does the plant grow every day. Maybe there was a documented experiment somewhere showing how many cm grow rate improvement using misting.

My opinion is just make sure you have 25-30ppm during photo periode.

[aquarius]

The reason behind putting the diffusor near the inlet tube is so that the mist/CO2 will be sucked into the filter, giving the CO2 more time to be mixed with the water before it comes out from the outlet tube (much like NA's external reactor).
The impt thing in this case is the positioning of the outlet tube to ensure that the well mixed CO2 is properly distributed around the tank.

[Jaffar]

Thank you for all advice. Both locations seem feasible. I guess it depends on preference and different experience of users.

[Midori]

IMHO, it is not a good idea to be near the inlet. You will risk building up air column in the filter if too much is taken in. Filter might got air lock anytime.

If you want mixing for better efficient, the External CO2 Reactor by Mr Chan is after the filter and not before.

It is better to put it where the outflow can drive the tiny co2 bubbles all around into the water.

[Jaffar]

Thanks. I guess that is one good reason not to put the diffuser too close to the inlet of the filter. Personally, I prefer this option.