Thought I would continue this thread here (A few ideas I want run by you all !)

OK, my Mazzei Injector arrived today. I'm gonna set it up tomorrow and see what results I get.

Tom, on your earlier post, did you really mean use a 600G pump to drive the injector or was it supposed to be 600L?
I'm gonna use a 1000L pond pump to feed the injector, then pass the injector outlet into a T at the return pump inlet. That sound OK?

Well, I've got it all the CO2 equipment set up but I'm having trouble keeping CO2 levels up. The Mazzei injector work fine. I get a nice mist of CO2 throughout the tank.
Even with a continuous stream of bubbles I struggle to push pH below 7.0 (kH is around 7) and my test indicator only just turns green. If I turn off CO2 the levels fall rapidly whereas my corner tank takes hours for the level to drop.

My suspicion is that the sump is gassing off in the return chamber. The weir has a minimal fall and I get little disturbance but it has about a four foot fall and I find the water foaming quite a bit. I just can't stop the return pipe sucking air down with the water. In the weir is a Durso style arrangement.
The pipe is a 1¼" through the bottom of the weir and into the sump via two 45 elbows. At the sump water level I put an elbow in and run it along just under the surface for 10". I've tried several arrangements but can't minimise the disturbance. If I run the pipe to the bottom, the air bubbles up so wildly it drives water over the top of the sump. You guys have far more experience than I do and I like to hear your suggestions

Have you sealed off the lower wet/dry biotower?

You should, that's where the gas is leaving if the overflow is only 2-4".

Regards,
Tom Barr

Hi Tom,

The water falls no more than 1½" in the weir.

This sump doesn't have a bio-tower or wet/dry area, I got rid of all the gubbins and just run simple sponges. It's divided up by baffles into four chambers;
1. Return area. This is where all the foaming is occurring.
2. Poly filter area
3. Course and Fine sponge area
4. Return pump, heating and CO2 equipment

I would just like to know how I can get water to fall 4 foot down a 1¼" pipe into the return chamber without inducing too much foaming as the return pipe seems to be dragging air down with it.
Tomorrow I'll borrow a digi-camera and try and post a shot of the return pipe and sump.

That inflow area is where you are losing the CO2.
If you seal that to the air above, eg, add the Biotower back and plug up the air vents etc, this will solve the issue.

The foam is actually fungi and lipid proteins.

Regards,
Tom Barr

Forgive me for asking so many questions, but.... !
The sump didn't have any kind of Bio-media tower.

The plan for my sump is on a Word document attached (had to Zip it first to get it to upload). As you can see, water flows into area #1. If I seal it off and pass the water through a tank connector would this be sufficient?

I assume that I'm looking to keep the gas contained so that it can still re-mix with the water? However, I don't think it's just CO2. The drain seems to pull atmospheric gas down with it as well. Does this tend to build up in the chamber? If so, how I dispose it?

Let me offer you a much better design that will provide better bio and better mechical and be very easy to deal with.

You'd figure after 30 years, I know what is practical and works and has built in redundancy

I'll make a drawing and post it.

In this drawing, the tower is a simple tube or box shape with a bulk here fitting at the top.

So the top is sealed, but removal able. You add a rubber seal, much like those weather seals they use on doorways etc and on car doors etc.

So it just slips on or off but is sealed from allowing gas in/out.

The yellow is a large piece of open cell 30 pore/inch that's large reactangle shape etc. This will stay very clean over all and require a good qeeze maybe once every 2-4 months.

The sock looking thing is the key to this design.
That's a cheap bag filter. They use micron rated filter pads, sop 100, 50, 20, 5 and 1 micron ratings maybe used.

Some add a sock in a sock. So add a 100mic inside and then and 5 micron on the outside of that to prevent rapid clogging.

The dotted line is just some egg crate that allow the ring on the bag filter to remain stable and supported. You can glue some small piece of plastic to support the egg crate there.

Now if you are really into things, this design allows you several neat options.
The air gap inside the tower with the bag?

You can add some air line to the and drill a hole and connect that air gap back into the return pump's suction side.

This will produce a mist effect and will be a mix of both degassed CO2 and air that was sucked into the over flow. Note: the air may displace some, but not all the
CO2 in solution. How much would tough to figure out I'd think.
Still, some recycling would occur of the deegassed CO2 also. Hard to say if they trade off would help.
Still, an interesting notion.

The other thing is to simply leave air/CO2 degassed gap alone and allow the filter to slowly dissolve it in the sealed tube/box. You do not want to make the chamber too gas tight, other wise it can fill up with gas and block flow, some slight leaking out is fine in other words.

Bag filters as they clog will simply over flow into the sump, so they are not an issue if you neglect things. I keep a pair handy so I can replace them fast. I just soak them in bleach for 1-2 hours and rinse and allow to dry till they are needed again.

The other optioin is to add a sealed bioball tower right before the bag filter. Basically you add one more chamber, and the water from that flows out into the bag filter via pipe, then the rest of the system is the same, the bag filter section does not need to be sealed in that case.

See other drawing for that. You can add the CO2 recirculation loop into several points also and fuse it with the venturi/reactor or add to the return pump suction side or feed into the CO2 reactor's pump's suction side as well.

A UV loop may be added prior to the CO2 reactor pump or in line with the return pump(better) and adding a heater etc is a good idea for most tanks

The other thing that can be added: a float switch to add replacement water for evaporation.

Plumbing the line to the tap water works well as there's not much Chorine/chloramines per day etc. But adding a carbon filter to the tap water, will remove that issue and allow you to do water changes by draining the tank slowly with a solenoid/timer for an automated water changer.


Regards,
Tom Barr

Thanks Tom,

I'll have a good read through this tonight.
Who knows, maybe I won't have any questions

Yea, ya will

Just consider the models I've shown you there.
The sealed, semi sealed cap as the tank water comes into the sump is the key.
The bag filters solve the mechical filtration issue the best way
Bioballs and/or a large sponge takes care of the biological side and you also will reduce both noise and evaporation by sealing the inflow to the sump.

If you want, you can add Purigen or activated caron or zeolite etc for chemical filtration in the sump.

You can add the CO2, the heater, the UV and have only the in/outlfows in the tank.

If you glue cork bark to the overflow/pipes in the tank and cover it with plants, you will not even see that.

My 90 gal from 15 years ago had that.

Regards,
Tom Barr

Hi Tom,
Thanks for the drawings, I now have plenty of ideas.

I have the heating and CO2 equipment in the sump already (The Mazzei injector is pretty effective BTW)

The sump is made from glass panels. If I can remove the end two that will leave me plenty of room to add filter bags and a cover. However..!
Filter bags aren't something available in the UK (as usual ) All I can find are media bags.
Is this what you mean > Filter Bags If so, do you know (or does anyone else know) of a supplier in the UK?

For the moment I've just drained the tank so I can put in the substrate etc so I'll make any mods before I refill.