# DIY Co2 Reactor and Water Change System



## Laurie Chatterton (1 Jan 2011)

I was a bit bored over xmas and thinking of a better way to diffuse my Co2 and get the flowrates up in my 48" tank, after browsing around a bit I spotted Ed's DIY reactor with 50mm PVC pipe, it got my mind working and I decided to kill two birds with one stone.

I have a Fluval 305 external as my filter with a single Hydro Nano 1600 for additional flow within the tank, Co2 from an FE is by an AE disc which does a job but I do not think it gets all the way round the tank and decided to go the external reactor route. While looking at this I decided to use a separate pump/powerhead to power the reactor as my filter is not going to be upto the job. This got me thinking with a closed loop feeding the reactor from the pump back into the tank via a spraybar I could possibly use this for increasing my flowrate and helping my water changes with a couple of additions.






So here goes, Ed's reactor intrigued me and decided the design was perfect for my application with just a couple of tweaks, I am planning on hanging it over the back off my tank as my canopy overhangs at the back giving me a void behind the tank and a little more headroom to work with over the 18" tank height. First mod was to change the inflow to the reactor by fitting a bend at the top to get my input line from the pump on the horizontal, the second was to put a second 90deg elbow on the outlet to create a U bend to feed back up to the spray bar. This is the primary circulation route with Co2 being fed into the 20mm od line to give an initial mix as ED described, also I will include the bleed valve to remove excess air after cleaning. So the Reactor Loop is fed from an internal Pump 150-1000lph pump via 20mm(od) pipe to the Reactor inlet, the reactor will be 40mm od x 460mm clear acrylic plus bends, the outlet from the reactor will feed the 20mm od x 1000m clear acrylic spraybar via 20mm od pipe, Co2 will be added at timed cycles but the pump will run 24/7.  

Right that will sort my Co2 and flowrates out I now have 750lph filtration flow from my Fluval 305, upto 1000lph from the reactor loop (less losses) and my Hydor nano 1600 to reach the parts missed by the others so I should be somewhere around the 10x on my 215 litre tank. Next lets think about the water changes, I already have a 650lph pump that I throw in to empty the tank when doing my 50% water changes and that gave me an idea. Fit a non return valve on the reactor pump outlet to prevent backflow when filling and two isolation taps either side of a tee, tap 1 feeds to a hose adaptor initially with the hose to drain, tap 2 feeds to the reactor inlet. Under normal conditions tap 1 is closed and tap 2 is open flow is through the non return valve (NRV) and tap 2 into the reactor then back into the tank via the spraybar. To empty the tank tap 1 is opened and tap 2 is closed flow is now through the NRV  and tap 1 to drain, run the pump until the desired level in the tank is reached (50%) then stop the pump. To fill the tank get the mixer taps to the desired temperature open both tap 1 and tap 2 and connect the hose to the mixer taps, flow is now through tap 1 and tap 2, the NRV stops flow going back through the pump, the fresh water is fed through the reactor and into the tank via the spraybar, this should have the added benefit of little or no disturbance to the tank from the incoming water. When the tank is full close tap 2 and remove the hose, add water treatment and turn the pump back on to help mixing, job done tank back in action minimal fuss.

I am thinking about the best way to impliment the spraybars from the filter and the reactor loop, my initial thought is to use two full length clear acrylic (20mm od) spraybars with the filter loop feeding from left to right at the top of the tank with the reactor spraybar just underneath this from right to left. This may help with further mixing of the Co2 laiden water and both flows should intermix giving a good circulation from rear to front, also the dead spot at the left where the filter spraybar enters the tank will be covered by the stop end on the reactor spraybar and vice versa.

I will start to aquire the components this month and hope to have it running before feb.

Any thoughts on this configurtion would be appreciated.

Laurie.


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## foxfish (2 Jan 2011)

I would be interested to see the non return valve design?


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## Laurie Chatterton (2 Jan 2011)

Non return valves here

http://www.norfolklights.com/barbed-non ... -2190.html

12,16 & 20mm all Â£5.49 Each


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## foxfish (2 Jan 2011)

OK thanks although the link does not give much away about how they function.
Unfortunately, from my experience anyway, non return valves are a source of concern, there are various designs but, probably the most reliable are the spring retained, ball valve & O ring type.
However all the designs have potential to fail & even the best designs tend to restrict flow quite dramatically.
You reactor design is tried & tested but, I would say the longer the reaction chamber the better & if you can use clear pipe so much the better.


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## Laurie Chatterton (3 Jan 2011)

Just been thinking about it again and will change the orientation of the pump side by moving the pump outlet to the through side of the tee (where the hose connector is) and putting the hose adaptor onto the mid point of the tee, this will give maximum unrestricted flow when in normal operation. I am going to change the hose adaptor to a female version with aquastop so should not need a NRV or tap on this side, anyone used the hose adators with aquastop are they any good or shuold I put a bung in the hose connector when in normal operation.


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## Coiln3107 (8 Jan 2011)

Laurie if you are talking about the Hozelok Aqua Stop valves they are very restrictive in there internal diameter. I dont use any on my aquatic setups but recently fitted on to the garden hose and launched it later that same day in the bin.   Where at full stretch the day before the garden hose still produced pressure it was down to a trickle. You could possibly use a stop or lever valve in its place. You seem to have it all sorted but just a thought. Just about every fitting will produce a restriction due to reduced internal diameter so as they add up with the changes in direction and friction on all internal surfaces as algea builds you may need a fairly serious pump. I have a very similar setup and started of with the Eheim 1048 600l flow pump and ended up having to get the 1260 2280l pump! I never would have beleived that in a 260l tank  that would have been necessary. I thought an extra 600l flow would be plenty.   I really was shocked. But have fun and keep us posted it looks great!


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## Laurie Chatterton (8 Jan 2011)

Slight change of plan gone for one of these to replace the two taps and hoselock

http://cgi.ebay.co.uk/20mm-3-4-Three-Wa ... 4&x=10&y=3

I will use the straight through route from the pump through the 3-way tap and into the Reactor, the only restriction in normal use will be the 15mm internal bore of the tap and the reactor itself, the restrictions will come in during the water change so no worries there as it does not matter. Just need to sort the 4mm fittings for the bleed valve and Co2 Inlet to the 20mm, starting to look a compact result now.


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## foxfish (8 Jan 2011)

I think that is a "set valve" it will work OK but they are designs for irrigation & have a very stiff function, so once set the valve stays in position.


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