View Full Version : Sump with NO CO2 loss

06-18-2009, 03:03 PM
I have not been doing the planted tank thing long as I have only been doing it now for about 6 months but in that time it would seem I have found a way to use a sump, DIY CO2 and make it work.

Please keep in mind I do not write these kinda things so I hope I say all this in a way everyone can understand.

I did have a reef tank and decided to go the way of a planted tank instead. So rather then purchasing a new tank and such I converted what I had. I have a 90 gallon reef ready tank with an internal overflow and a 30 gallon sump below the tank.

Now most people say a sump can work if you seel it off and the main reason they do not use sumps is because of the CO2 loss.
The big problem when using CO2 is keeping it in the water which means no agitation if possible as to where a reef tank is designed to do just that... Agitate the water.

Well I have created a system where the sump is in fact not closed and I have no CO2 loss. Here is how I did it....

As anyone who has had an internal overflow knows, the water streams through little slices within the plastic of the overflow then spilling over into the overflow holder at which time the water either falls into a pipe (very loud) or they have a pipe system to where as the water rises its pushed into and down the pipe to the sump which is what I have. The key to this first part when not wanting CO2 loss was to raise the pipe in the overflow enough so that the water outside the over flow matches the water level inside the overflow therefore there is no water agitation at all!. If fact I have floating plants as well with an overflow because there is not really a suction due to the fact that as the water level rises in the tank it pushes the water into and down the pipe to the sump.

Now for the next part.... the sump.
This was the tricky area. As the water goes down the pipe and into the line it does take with it air however because its trapped in the line nothing escapes not even CO2. Where the line meets the sump I have created my own sort of wet dry if you will. Now I am sure you're asking yourself... Wet dry! I thought that would degas as well? Well if it was a normal one you would be correct. Here is how I did my wet dry...

I went to the store and first bought two of the exact same plastic containers without lids. In the first one I cut a rather large hole in the side towards the bottom. Then I placed the other plastic container inside the first one which because they are the same only goes so far down leaving about 3 inches of space between them. I then drilled holes the size of nails all over the bottom of the second container to allow the water to flow through to the bottom one. I then filled the second container with bio balls. After this, I also purchased a small 3 drawer plastic unit... Something like somebody might using for keeping thread and needles in or screws or what have you. I then removed two of the draws from the bottom up and cut the legs down so that the unit only holds one drawer. I then drilled 4 holes in the sides and used zip ties to attach the drawer unit to the 2 containers we started with. I then removed the drawer and drilled holes all in the bottom again the size of a nail. Then purchased some filter pad for about $6.00 at the pet store. You get a ton of filter pad when you do it this way. Saves big time $$$$.
I then cut the pad to fit perfectly in the drawer. I then can slide the drawer back in the drawer unit and bingo! Instant big filter. I then drilled hole to fit a bulkhead in the top of the drawer unit and placed a bulkhead at which time I then attached the line coming from the overflow to the new filter.

Now the sump is filled with water right up to the bottom of the drawer.
When the system is active water goes up the pipe, down to the filter pad where it exits right on top of the pad then flowing through the holes down through the bio balls, out the big hole in the container on the bottom and then to the return pump where it is blown back into the tank under water. Because the sump is filled to the bottom of the drawer and keeping the bio balls under water there is NO water agitation at all.

I have 3 2 liters of pop that was washed out and created a DIY CO2 system with these which has a air line that goes right to the return pump so that when the bubbles come out they are sucked right into the pump which then chops them up very very small and shots them all over the tank which really gets the CO2 everywhere! Little tiny tiny micro bubbles that are so small they never seem to even rise to the top... they just vanish.

After running this system for 4 days my plants exploded!

I will post pictures later today of the sump, wet dry, and the rest. I hate to call it a wet dry because its really not as there is no dry part. But the point is that a sump works and works VERY well without sealing it and without CO2 loss.

What made me do all this? One thing. I hate canisters.
I do not care what anyone says they all leak sooner or later and a sump has way more benefits then a canister ever will for a tank.

.... More water mass
.... Keeps the show tank topped off
.... Easy to hide equipment
.... Great place to add water and medicate which is less stress on fish
.... Holds much larger filtration

And much more!

I know I know.... Yeah but what happens when the power goes out and the sump floods?

Oh how I hate that question. The fact is the whole trick to a sump is not to fill it to the top and to allow for water build up if the pump stops.

My system when the power goes out dumps the water into the sump till the overflow intakes are above water then it stops. The sump fills to near the top and that's it. No floods, nothing to worry about. Too many people fill their sump right to the top then wonder why they end up with a flood. its called user error.

So that sums it up! I will try to add pics in a bit. Canister lovers don't send me hate mail :-) I just think they are over priced, cheap quality, and designed to suck $$$ from your wallet.


Chad Hughes
06-18-2009, 03:31 PM
Your design is interesting. I think I need to see a picture though. I'm trying to wrap my mind around what you are describing, but I need some help. LOL! I guess I'm more of a visual person.

Anyway, how do you know how much CO2 you are using? DIY CO2 is not metered or controlled, therefor you really can't tell how much you use or waste. With pressurized systems you'd be able to tell more accurately. Just the activity of the controller is a big indicator. If the solenoid is off more than it's on, the you aren't "wasting" too much CO2. If it seems to be on all the time, then it's likely that you are throwing CO2 out the window. I use sumpis in both of my show tanks and have minimal CO2 gass off. They are standard sumps.

Thanks for the info! Very interesting!