Reactor Problem

[Flohrie]

I've made a reactor for my DIY Co2.

I use 2 Juice bottles going through a gang valve and then into the tank by use of airline.

Now my reactor is the common powerhead/gravel vac type, the problem is when i turn on the powerhead it pushes water up the airline and the co2 cannot create enough force to push it out, I also don't have an airstone fine enough to put on the airline. The airline is going in horizontal and the gravel vac doesn't really allow it to go vertical (would making the airline vertical fix it anyway?)

Any suggestions for fixing it?

[djlen]

If you are running the air line up into the intake of the power head you shouldn't be experiencing it pushing water into the air line, UNLESS you have the power head on reverse flow. If the power head is in the forward flow mode it should suck the CO2 out of the air line and up into the impellor and out into the siphon tube to be dispersed into the tank.
I don't know what you mean when you say the gravel vac doesn't allow it to go in vertical. The air line shouldn't be any where near the gravel vac. As I said, the air line is attached to the intake of the power head. If you are trying to attach the air line to the gravel vac, that may be the reason you're having the problem.
Len

[Flohrie]

Sigh....I get it now :o


I was just following some diagrams I saw on the net, silly people they are :rolleyes:

Thankyou djlen!!

[plantbrain]

Careful not to suck out the brew of the bottle.

Use a rigid juice bottle or a glass bottle etc so it doesn't collapse on you.
This sometimes ocurrs after a rechange as the warm water cools and condensed creating negative pressure inside the seal bottle. Sometimes this enough to collapse the bottle and push the brew out and into the suction side of the pump.

Regards,
Tom Barr

[Flohrie]

Thanks Tom,

My bottles are pretty rigid and I'll have to keep an eye on it after my next change :)

[plantbrain]

Just make sure you leave enough space near the top of the bottles so that when the yeast start producing froth, none gets pushed out and into the tank.
Keep the water level 6-8cm down from the lid.
It should never be an issue then.

Regards,
Tom Barr

[djlen]

Flohrie, one other thing I experienced that you might run in to is that if you have really good flow out of your power head it'll blow the sponge out of the gravel vac tube. Just get a bigger sponge and jam it in there. I started by using an AquaClear Mini sponge that I cut in half. Now I use the whole sponge and it stays in.
Len

[Flohrie]

Haha guess what........My sponge got blown out :)

Time for a bigger sponge.

Oh also what if I had no gravelvac bit on the end?? And i just let the powerhead blow out all those little bubbles, would this result in good diffusion or is it wasted as soon as the bubbles reach the surface?

[djlen]

Don't know what you mean by gravel vac "bit" on the end. Most reactors of this type are run open-ended. The sponge should give you a nice mist for the most part with a larger bubble every now and then.
Len

[Flohrie]

Well what I'm trying to say is that my powerhead chops up all the bubbles and they come out as a mist anyway so do I need the tube on the end at all?

[Skittyfish]

Flohrie-my understanding of the gravel vac reactor is that the longer the CO2 bubbles stay in the tube the more of it gets disolved into the water, the fewer bubbles you are blowing around your tank. That is why some designs show the CO2 line going into the vac tube instead of the powerhead. The water pushing through the sponge causes the CO2 to break up even more.

At least that's what I thought. I am sure someone will correct me if I am wrong;) .

[djlen]

As usual, Skittyfish is correct-o-mundo. The bubbles coming out of that vac tube are almost imperceptible. They are like a very fine mist. I have to look closely to see them.
Len

[Flohrie]

Ok thankyou both very much :D

[JPT]

I had the exact same problem with water overflowing into the CO2 line. If you are supposed to pipe you CO2 line into the intake of the powerhead (instead of directly into the gravel vac tube), I think that some of the suggested gravel vac diffuser designs online are incorrect.

I guess that's how the bubble bounces.. :)