REACTOR FEED QUESTIONS????

[Canadian Man]

So Tony and I made a copy of DJ88's reactor with a 26" tall tube in 6" acrylic.
The reactor is comming off line on friday to do some plumbing adjustments. It's been running for 3 weeks now and it works wonderfully and keeping my levels where I want them.

The problem I am having is the feed:
- My sump is in the basement and the return pump is a LG4. The feed for the reactor is currently T'ed about 6" off the pump.
The feed origionaly had a John Guest Ball valve to slow down the input but it pluged after a day cause it could only be opened about 1/5 of the way.

So yesterday I put a 3/4" ball valve from the same T point in the return line and added the JG valve after this T. The reason for this is so the JG valve can be fully open and the control is mainly with the 3/4" valve.
Now this 3/4" ball valve can only be opened a crack or the flow is too fast.

Anybody have any suggestions or questions if more info is needed.

I guess I am worried of blowing up my reactor. If I restrict the output and let the input run open then the rectangular base of the reactor swells!

[StirCrazy]

Is the reactor in the basment also? if so why not get a little 10 gal/hour power head and use that to feed it.. I do that and use a iragation drip valve on the output to controle the flow through mine at about 2 gal/hour.

Steve

[reefburnaby]

Hi,

I would probably get a Minijet or a Maxijet 400 and use that to feed the reactor. They are small, quiet, power efficient and they can sit in your sump. The backpressure of 16 feet of water is probably causing some of these problems.

- Victor.

[Delphinus]

Interesting points. Wow, I never thought of that.

Bear with me as I try to think this through though. Wouldn't you negate the effects of all that head pressure by throttling back the input valve? I.e., if the JG valve or the 3/4" valve is mostly closed, won't the pressure in the reactor not be all that high?

Or is it that .... because the irrigation valve on the effluent output is throttling back the output, thus creating a tendency within the reactor to pressure up slowly .... and since the feed line on the OTHER side of the valve is 17' head pressure, the net effect in the reactor will be to creeep upwards to the point that both sides of the inlet valve are equalized? And thus the reactor would also be under 17' head pressure (or whatever).

I guess what I'm asking is .... just because it doesn't pressure up all the way immediately; doesn't mean that it won't eventually pressure up all the way???

:shock:

Oh my. If that's the case, then that mini-jet is looking better and better.

[Delphinus]

Ok, thinking about this some more.

Let's assume that my supposition there is true (i.e., as long as the output valve of the reactor is set to a value less than that of the input valve, that there is a tendency for the reactor to pressure up to match the sump return line pressure).

Wouldn't another alternative to feed the reactor be, keep the T off the sump return line, but place both the JG shutoff valve and the irrigation valve on the reactor input. Control the effluent rate of the reactor by controlling the input only. The JG valve can be mostly closed to keep the pressure not too high in the 1/4" line, and the irrigation valve (since it's a needle valve basically) can be used for fine tuning the actual drip rate. The effluent line is basically fully open at all times.

I suppose one drawback to this idea is that it will take seemingly forever for an adjustment to have an effect.

Is another potential pitfall that the reactor may drain itself by siphon, and the water level drops to match the water level in the sump? Or I guess that would only happen if the reactor is not airtight. It does make me wonder if there will be a negative pressure on the reactor (for the water level to pull itself down via the effluent line).


AArrrgfghhh!!!!! Are you guys basically saying we made a mistake by T-ing off our sump return? I thought lots of people did it this way ?? !! ???? :? ?????

:?:

[Canadian Man]

Tony: I dont think it's a mistake to T the return line.
I have mine above the height of the reactor and it dosen't drain when the pumps are shut off. I havent been running anything on the reactor output, just using the valves on the reactor input to try to control the flow.


Steve;
Yes the reactor is in the basement sitting beside the return pump.
I have thought about getting a pump to feed the reactor and I do have a little 2.5w pump that attaches to airline tubing but I just didnt want to have it attached to another pump. I like the clean look of having it attached to my return pump if I could keep it this way.

Still looking for advice/help/guidance/light at the end of the tunnel :(

[reefburnaby]

Tony,

What you are describing is a variation of the Pascal Principle - water pressure is equalized on to all surfaces of a closed vessel. Although the water flow in to the reactor is slow, the water pressure will eventually build up if the reactor outlet has flow control.

As for a solution, your trick with only using the inlet valve as the control works. This will prevent excessive pressure from being built up in your reactor since there is no/very low backpressure (or head). The drawback is that it is difficult to control. I wonder if they make a PVC needle valve for this type of application ? You can try moving the outlet valve to the inlet side of the reactor -- sort of a back to back valve configuration.

BTW, this is why most houses use pressure regulators to control water pressure within a house. Valves can control the flow, but it doesn't stop pressure from being built up to dangerous levels when the taps are closed.

Hope that helps.

- Victor.

[Canadian Man]

Thanks Victor.
That does help.
I am currently talking with Jayson and he has a trick little needle valve that I am getting from him that's made of plastic and should hopefully do the trick.

[ldzielak]

I have been fighting the same problem for almost a year now. My reactor supply is T'd off my skimmer pump (Iwaki 55RLT) This pump puts out 17 PSI, every valve I have used is barely open and I had to make an inline floss filter to keep the valves from pluging. I have to re adjust my flow every 3 days or so. I think the only way is to T off a low pressure pump or use a powerhead.

Lee

[Canadian Man]

Well here's an update.
I cut off the end of the reactor to do some changes with the plumbing set up.
When I re plumbed it I added a few extra T's with plugs so I could fool around with the plumbing. So anyway I have two inputs before the intake of the recirc pump and one is where the CO2 enters and the other is the gravity feed from my sump.

WORKS AWSOME.
The reactor has been up for 27 hours now and it is still rock steady at 80ml/m. even with some airbubbles in the intake 1/4" tube and the output it is steady.

Thanks.

[Delphinus]

How many people have gravity fed reactors fed from the main display tank?

Unlike Canadian_Man I can't put my reactor underneath my sump since my sump is at ground level already. So if I were to reap the benefits of gravity feed, I'd have to have the reactor intake in my main display tank.

Problem with this is, unless the reactor output is also in the main display tank, then my reactor is suddently a very slow overflow. In a power failure, the water will continually drain into the sump via the reactor, until the siphon is broken. So there is sump overflow risk in my scenario. If you look at my signature you'd understand why I have reluctance for this idea. Plus there is the extra hassle of having to manually restart the siphon after power is restored.

The simple solution is to have the reactor effluent come back to the main display tank. If the input and output are the same, then there's no sump overflow risk from the reactor itself.

But, I'm not sure how comfortable I am keeping my reactor output in my main display? I wanted to have it in my sump so that any excess CO2 has plenty of opportunity to escape to atmosphere before being introduced to the main tank. Plus if the reactor effluent pH is 6.5 do I really want this introduced into the main display? Isn't the sump the place for reactor effluent?

Am I overblowing the risk of CO2 and low pH reactor effluent into the main system? Because that sure is the simplest solution.

The only other thing I can think of, is have the intake in the main display tank, the output in the sump, and have a solenoid shutoff for the intake that closes the intake in a power failure. Couple of drawbacks. The first obviously, where the heck does one get a solenoid valve for 1/4" tubing that's saltwater safe, and how much are those? Too much, I bet! And second, it's just "yet another" thing to plug into the wall, and there are too many things plugged in, as it is.

Advice please!!!

[ldzielak]

Tony,

If you drip the reactor effluent into the tank or sump, then if you had no flow and only CO2, then the gas, would never reach your water and affect you system.

Maybe you could drip the effluent close to you overflow, so it goes down your sump to be mixed and does not make it to you main tank for long? But if your source and return are the same level, you have no differential pressure and no flow.

I just drip my efluent and don't run a solenoid any more.

Lee