DIY Rex Grigg Reactor/Fluval 204 Problem - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 04-25-2011, 09:06 PM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
DIY Rex Grigg Reactor/Fluval 204 Problem

So I've been contemplating on getting a reactor for my pressurized CO2 system and finally decided to take the challenge and build a Rex Grigg style reactor.

As you can see below, my end result is more or less what I was shooting for.

The problem I came across, as you can also see below, is that the ribbed hosing of my Fluval 204 filter (outdated, I know) is too small to fit over the hose barb of the reactor.

The hose I'm pretty sure is 12mm (1/2 inches) and the hose barb is 3/4 inches.

Has anyone with a Fluval filter experienced this problem and if so how did you overcome it?

Is it as simple as getting a different sized hose barb? Would a different size fit into the two outlets of the reactor?
Attached Thumbnails
Click image for larger version

Name:	CIMG0831.jpg
Views:	102
Size:	30.3 KB
ID:	30242  

Click image for larger version

Name:	CIMG0835.jpg
Views:	166
Size:	51.8 KB
ID:	30246  

BwackBwack is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 04-25-2011, 09:25 PM
Wannabe Guru
 
flowmsp's Avatar
 
PTrader: (60/100%)
Join Date: Feb 2010
Location: Winter Haven, Florida
Posts: 1,024
Quote:
Originally Posted by BwackBwack View Post
So I've been contemplating on getting a reactor for my pressurized CO2 system and finally decided to take the challenge and build a Rex Grigg style reactor.

As you can see below, my end result is more or less what I was shooting for.

The problem I came across, as you can also see below, is that the ribbed hosing of my Fluval 204 filter (outdated, I know) is too small to fit over the hose barb of the reactor.

The hose I'm pretty sure is 12mm (1/2 inches) and the hose barb is 3/4 inches.

Has anyone with a Fluval filter experienced this problem and if so how did you overcome it?

Is it as simple as getting a different sized hose barb? Would a different size fit into the two outlets of the reactor?
What size hose barbs are those? They look pretty big, like 3/4 inch. Id take a look to see what size the fluval ribbed hoses are and try and find barbs to fit them. Ive heard of people using the non ribbed vinyl tubing on fluvals also.

Edit: Just re-read and saw that the barb is 3/4 and hose is 1/2. Im pretty sure they make 1/2 inch barb to 3/4 threaded barbs.
flowmsp is offline  
post #3 of 14 (permalink) Old 04-25-2011, 09:33 PM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
I'm on my way to Lowes as we speak to find out.
BwackBwack is offline  
 
post #4 of 14 (permalink) Old 04-25-2011, 10:34 PM
Planted Tank Obsessed
 
PTrader: (4/100%)
Join Date: Sep 2010
Location: Fresno, CA
Posts: 339
Yeah Lowes has the 3/4 NPT to 1/2 barb in plastic. Just no 5/8s. I bought 5/8s from Ace.
djscotty is offline  
post #5 of 14 (permalink) Old 04-25-2011, 11:03 PM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
Well the 1/2 inches barbs were the right size, but unfortunately I've already cemented all the pieces together and I can't find an adapter that threaded on both sides so the pieces will fit properly. Looks like I will building a entirely new unit.

On another note, who'd like to buy a completed Rex Grigg-style reactor?
BwackBwack is offline  
post #6 of 14 (permalink) Old 04-25-2011, 11:25 PM
Algae Grower
 
cheeman's Avatar
 
PTrader: (0/0%)
Join Date: Jan 2011
Location: Rosemount,MN
Posts: 113
WHY NOT JUST GET SOME 3/4 HOSE AND 2 SIDED BARB
http://www.google.com/products/catal...LoBEPMCMAc4Cg#
cheeman is offline  
post #7 of 14 (permalink) Old 04-26-2011, 03:13 AM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
That's a lot of google ordering for something I could just try and fix locally.
BwackBwack is offline  
post #8 of 14 (permalink) Old 04-26-2011, 03:45 AM
Wannabe Guru
 
PTrader: (0/0%)
Join Date: Aug 2010
Location: Wake Forest NC
Posts: 1,121
I'm not sure a Fluval 204 will have enough pressure to force water through your reactor. If it does, it will be very slow. That may be just fine for your application if it works but you may need to monitor it closely in case water flow is reduced even more by a clogged intake strainer.

Looking forward to seeing it in action though!
redfishsc is offline  
post #9 of 14 (permalink) Old 04-26-2011, 05:27 AM
Algae Grower
 
PTrader: (0/0%)
Join Date: Dec 2010
Location: New Zealand
Posts: 107
Why not just buy a 1/2" to 3/4" adapter?
I found one in my local hardware store in the gardening area with all of the usual hose fittings and junk that you use to set up home irrigation.
then all you need is a short as piece of 3/4" tube to go from the elbow to the adaptor.
DvsDev is offline  
post #10 of 14 (permalink) Old 04-26-2011, 10:58 AM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
Quote:
Originally Posted by redfishsc View Post
I'm not sure a Fluval 204 will have enough pressure to force water through your reactor. If it does, it will be very slow. That may be just fine for your application if it works but you may need to monitor it closely in case water flow is reduced even more by a clogged intake strainer.

Looking forward to seeing it in action though!
Thinking about it now, I think you may be right. That is a large pipe to move a lot of water through; what if it's not strong enough?

Maybe I will build a new reactor that is half the diameter. Would that work?

Has anyone with a Fluval 204 or something equivalent tried this and had it work?

Does anyone have a Rex Grigg reactor at all?
BwackBwack is offline  
post #11 of 14 (permalink) Old 04-28-2011, 11:00 PM
Planted Tank Enthusiast
 
milesm's Avatar
 
PTrader: (2/100%)
Join Date: Apr 2006
Location: HI
Posts: 711
you don't need to cement those hose barbs into the reactor, just use teflon tape. i would also use straight hose barbs, not the 90degree elbows if you are concerned about flow.

don't decrease the diameter of the reactor; i presume you used 2".
milesm is offline  
post #12 of 14 (permalink) Old 05-02-2011, 07:18 AM
Algae Grower
 
PTrader: (0/0%)
Join Date: Dec 2010
Location: New Zealand
Posts: 107
Seriously I wouldn't worry about your filter being too small, if you think about it there's not much difference between the reactor and a cannister filter as far as layout, water goes in one end and out the other, as far as "pushing strength" once the chamber fills up the flow in and out shouldn't be much different as there should be no restriction (so long as you didn't put anything inside the tube).
And if you are really worried about it, put it on the inlet side, let gravity do all the hard work.

As far as fixing your hose size "issue" just use 1/2" barbed fittings, it won't make that much difference to flow, if possible don't use angle fittings, that stuff will slow you down heaps (but so will ribbed hose anyway) just keep all lengths of hose as short as possible and lift the filter and reactor up a bit.
If you do have a slow flow then reduce the height difference between the reactor and the height of water in the tank, (gravity's a B***** and will fight you every step of the way)
DvsDev is offline  
post #13 of 14 (permalink) Old 05-02-2011, 10:34 PM Thread Starter
Algae Grower
 
BwackBwack's Avatar
 
PTrader: (0/0%)
Join Date: Apr 2011
Location: Charles County, MD
Posts: 46
An update on my situation:

After not being able to use the 2" diameter reactor because the threading for the hose barbs were too small and I couldn't find an adapter for a smaller size, I made a second reactor 1" in diameter.

I hooked up the new reactor (correctly this time; outlet through the top and out the bottom) and let it run for a little while.

It currently emits a constant stream of a few tiny bubbles, which I guess may be a result from shrinking the diameter of the reactor.

The only problem I seem to have now is that I have to run the bubble count higher than what I suspect I should have to. It's too high to count per second (I guess maybe 8-10 bps) and my drop checker is just barely green.

I know I'm not getting complete diffusion, but is ~8 bps normal for a 55 gallon tank?
BwackBwack is offline  
post #14 of 14 (permalink) Old 05-02-2011, 10:46 PM
Wannabe Guru
 
rickztahone's Avatar
 
PTrader: (15/100%)
Join Date: Jul 2009
Location: Pacoima, California
Posts: 1,346
Quote:
Originally Posted by BwackBwack View Post
An update on my situation:

After not being able to use the 2" diameter reactor because the threading for the hose barbs were too small and I couldn't find an adapter for a smaller size, I made a second reactor 1" in diameter.

I hooked up the new reactor (correctly this time; outlet through the top and out the bottom) and let it run for a little while.

It currently emits a constant stream of a few tiny bubbles, which I guess may be a result from shrinking the diameter of the reactor.

The only problem I seem to have now is that I have to run the bubble count higher than what I suspect I should have to. It's too high to count per second (I guess maybe 8-10 bps) and my drop checker is just barely green.

I know I'm not getting complete diffusion, but is ~8 bps normal for a 55 gallon tank?

i have a reactor on my 55g as well and with a 2" reactor and it's difficult to count the bubbles but if i'd have to guess i'd say 5bps and at the end of the day my DC is pretty much bright green boarderline yellow. The thicker diameter one would have been a better option. The barbs only needed to be tefloned, not cemented. I know an online site that sells all barb sizes and adapters if you want to try to re-use your other one. just simply cut off the end caps that you cemented and buy some new ones (like a buck each) and then get the correct barbs. the one you originally had looked on the long side to me any way. i can measure mine if you want to compare. Mine works great btw.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

FILSTAR XP3 PIMP #166
EHEIM 2213 PIMP #441


rickztahone is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome