[pipefish]

hey everyone,
lately my co2 ladder has been killing me and i am getting ready to replace it. I am planning on doing a diy mini powerhead reactor like this one http://www.floridadriftwood.com/product.asp?0=217&1=253&3=404 I dont want to buy it cause it costs quite a bit and doesn't look that hard to make and all i really need is the powerhead and the sponge. I have a few questions though. First of all, i have a 20g tank and its a shrimp only tank with snails so do you think any baby shrimp can get sucked into a rio? Even if they do, do you think they will be able to live? Also is the sponge really important? and lastly has anyone ever used this before? is it really effective (if you haven't used it do you think it'll be effective judging the design of it)? Thanks in advance

 

[brad]

This design is simpler. You can`t get much more effective either.
http://www.barrreport.com/gallery/showimage.php?i=1

 

[pipefish]

i don't want to use that design cause my 20g is a short tank and can't fit something like that in there, i really like this design cause its small and compact

 

[pipefish]

what is the venturi loop for??

 

[brad]

Tom explains it better than I ever could.
http://www.barrreport.com/forums/showthread.php?t=11&page=1&pp=&conly=1

His explination is the 2nd poste down.

 

[pipefish]

ooooooo ok so what tom is saying is that when the water can't hold anymore oxygen that means the co2 can't be diffused as well either, so the venturi loop is supposed to get rid of the excess oxygen in the chamber allowing more co2 diffusion right?

i might go to the lfs in a few days and see what kind of powerhead i can get, maybe one i can add a prefilter to then stick the diffuser on it. I just want to keep it simple lol if i have any bubble build ups i'll probably try out the venturi model tom made but all i want is something that can get me 30ppm of co2 and have no snails be able to stop it like what they are doing to my co2 ladder oh and on that reactor from floridadriftwood do you think i need to put the sponge on it? its gonna go into a timer so it'll turn off and on with the lights. thanks in advance

 

[anonapersona]

I will point out that if you position the pump as shown in that photo, with the grill facing downward, that when you do a water change that brings the water level below that level, the pump will airlock. Very easy to just make it so the grill faces any side or the top, otherwise you hav to tip it over to get it going again.

 

[pipefish]

ooo, hmm what if i stick it on the bottom half of the tank? it never occured to me when i was making it or else i could have tilted it. Maybe if it does annoy me i can rip it apart and do it again cause i'm anxious to try it out and see if it works well . I got a question though, does the outlet need to point a little to the top so it hits the co2 or is it alright if its just pointing parrallel to the top?

 

[anonapersona]

doesn't matter

I don't think it matters what way the outlet points, if you are taking about the pump outlet, or even the gas outlet I suppose. Mine was built with the pump on the top of the jar (I used a plastic spice jar for the clear tubing) and the pump outlet was facing down and over to the side a bit, this gave the gas bubbles, which entered near the midlevel of the jar a nice rotation which I think helps to keep them going until they disolve. I think that side entry, as long as it is near the top not the middle would be fine, as you'd still get that good rotation of the gas bubbles.

I think the rotation is important, and so you dont' really need a strong flow from the pump. If you use a strong powerhead, and the flow is straight down, you need to be more concerned about the bubbles being pushed out the end before they are dissolved, IMO, so you need a longer tube length and something to crash the bubbles agains to break them up. If you just rely on rotation, you can have a smaller tube I think.

As for pushing it lower in the tank so it wont' air lock, that works, but it creates more back pressure for the gas to push against to get out of the tubing. Not an issue for pressurized gas, but for DIY, it may lead to lower input rates or greater pressure in the generator which might create leaks in weak spots at connections. I lived with the need to tip the pump over to get the air out for nearly a year before I finally realized what was going on and fixed it. Sometimes if the water change is less, there is no problem.

 

[plantbrain]

i don't want to use that design cause my 20g is a short tank and can't fit something like that in there, i really like this design cause its small and compact

It's no bigger than the FD item, both are the same size 4"x2" and the powerhead is either on top of on the side, unlike that one, mine has no need for the sponge, allowing only clear tubing. Anyway, put some stem plants back near it so it's hidden, that's not hard.

If you want, use a cansister and make an external CO2 reactor.

Regards,
Tom Barr

 

[pipefish]

ok well i made the design according to the website and if it messes up i might change it to your design Tom. But if its working out great i'm just gonna try to keep it as simple as possible and not mess with things. On the design from the website I had to stick th sponge in cause the bubbles kept coming out but i guess it was cause the powerhead was a bit fast and i had a lot more bubbles when i tested it then now. But its working out great now and all my plants are pearling an hour after i put it into the tank. I dont know if the pearling is a good thing to you plant experts but in my mind the pearling is a sign of sufficient co2 I also tested the water and i got like 7.0 pH and 14kH which if i remember correctly is between 25ppm to 30ppm (too lazy to check the chart ).

 

[pipefish]

ok when the lights went off i noticed a big bubble was collecting in the tube so should i drill a burp hole in it? If so where should i put it? Above the powerhead reactor outlet? or under? If above then wont all the bubbles fly out? if below won't the powerhead no be able to start up because theres a big bubble in it? Tell me what you think thanks.

 

[plantbrain]

Yep, about 2" or so down, slightly below the venturi. this will prevent the tube from inverting as well as gas locking the powerhead.
It'll also leak out excess CO2 if you add too much.

By directing the outflow from the powerhead to hit thwe side of the reactor tubne instaed of shiooting out the bottom, you no longer need a sponge.

The tiny bubbles that are expelled get dissolved and greatly increase the ability of the reactor to add more CO2 to the tank. It might seem wasteful intially, it is not.

This only occurs after the CO2 levels rise high enoyugh to build up a gas bubble and then when it gets to the predetermined venturi level, it starts pumping the gas out even more and wasting it some.

The O2 build up is removed this way.

Yes, the plants are doign much better from the sounds of it.

Remember the plant's response now.
That's what you want to see, if not, check the CO2.

The nutrient routine is easy now once you have good cO2.

Keep it up.

Regards,
Tom Barr

www.BarrReport.com

 

[pipefish]

ok great to hear it wont be a waste . I'll will be drilling a hole a few inches below the outlet so the bubble doesn't get too big . Thanks for the help.

 

[pipefish]

ok its been like 5 hours now since i made the burp hole and there is much less bubbles in the chamber spinning around, is that bad? Also none of the plants are pearling anymore the only one is the anubias leaves on the bottom and i figure that it wasn't as much co2 as yesterday cause it doesn't take much to make anubias pearl since its a low light plant. Do you think i should just wait longer? Should i keep the diffuser on overnight? I dont think it'll be a problem because i have an HOB that is giving off a fair amount of o2 hopefully but right now i have it connected to my timer along with the lights and no problems yet. Plus my kH is 14 so it takes a lot to move the pH around.