Solenoid Valve - Needle Valve

[hwoarangtag]

Hi,
I read something a few articles on co2 regulator. I saw 2 terms that appears often, solenoid valve and needle valve. From my understanding, both are used to control gas pressure flow. I would like to know what is the difference between them and which one can be used as CO 2 regulator.

THanks

 

[raptorrex]

Hi,
I read something a few articles on co2 regulator. I saw 2 terms that appears often, solenoid valve and needle valve. From my understanding, both are used to control gas pressure flow. I would like to know what is the difference between them and which one can be used as CO 2 regulator.

THanks

as far as i know, a solenoid valve is simply on and off, via an electronic switch. a needle valve is variable, the needle is conical in shape, and operated by hand or electronically

 

[hwoarangtag]

then is both needed for a perfect CO2 planted aquarium? or only the needle valve is needed provided that the flow of CO2 is low.

 

[chr15_8]

i assume your running/thinking of running pressurized co2?

is yes then you need a needle valve. a needle valve lets you ajust the amount off co2 going into the tank.

a solenoid valve is plugged into a timer to come on/go off with your lights. therefore you are only adding co2 when the lights are on/plants are absorbing it. (some people time it so the co2 comes on for about an hour before the lights do so that there is plenty of co2 in there for when the lights do come on) people dont use a solenoid valve on diy co2 only on pressurized systems.

you will need a regulator aswell, the co2 in he bottle is around 52psi the regulator then allows a small amount of co2 out, then the needle valve is used to get the co2 amount correct

im sure someone will correct me if im wrong

hope this helps
chris

 

[TwoTankAmin]

Actually, a solenoid can also be connected to a Ph meter so that the solenoid turns the co2 on and off in order to maintain a specified pH in the tank.

You must have a needle valve with pressurized co2 in order to obtain the fine level of control needed. The regulator steps down the pressure from the bottle and then the needle valve regulates the flow of that lower pressure co2.

 

[SuperColey1]

Yep as stated above.

Needle Valve is compulsory (unless you want to kill your livestock)

Solenoid Valve is optional. I don't use mine anymore and leave my pressurised on 24/7 but drop checker is defo needed to make sure that you're not ODing through the night.

Ph/CO2 controller IMO is pointless as it is not the Ph you are aiming to control. CO2 needs to be consistent and a controller shutting it off every time the Ph reaches a certain point renders your CO2 inconsistent.

Once you get the CO2 at the right level you shouldn't have to tamper with it for months until the bottle runs out therefore your Ph should remain stable (unless your tap water suddenly changes)

Andy

 

[hwoarangtag]

So is regulator = needle valve without the gauge?

 

[SuperColey1]

No

A regulator is basically the output from a gas cannister and can have no dials or many.

For welding not too much accuracy in output is needed so they don't need the needle valve.

The regulator on its own can self adjust slightly so we use needle valves for a more precise output level thus not killing the fish.

The needle valve screws into the regulator or sometimes inline.

Andy

 

[TwoTankAmin]

Actually, controlling co2 based on pH is likely the most consistent method for doing so. Instead of ever having to adjust your flow rate because of new plants added or a major pruning, the solenoid and pH meter will give a more consistent level of co2.

This is a regulator (dual guage):

These are a needle valves:

 

[Themuleous]

It might be easy but that's not to say it isn't without risks, ie the pH probe coming out of the tank and the kit pumping co2 into the tank. To me the pH probe is an unnecessary expense. if you have a spare 100quid then I'm not saying they are unless but to me unnecessary. There is also the issue of water changes and shifts in the KH of the water. I would think the probe would need more calibrating too, I have been running my simple set up (not even using a solenoid!) and I've not had to change the bubble rate once in the three months its been running.

Sam

 

[Dave Spencer]

Actually, controlling co2 based on pH is likely the most consistent method for doing so. Instead of ever having to adjust your flow rate because of new plants added or a major pruning, the solenoid and pH meter will give a more consistent level of co2.

I would have to disagree with this. The key to CO2 is stability, and with a pH controller switching the CO2 on and off, you may struggle to achieve this.

I have pressurised CO2 on three tanks using a drop checker to measure the levels, and I haven`t touched a needle valve in months. There are several factors affecting the pH in a tank, but it is using the CO2 drop checker method that only measures the effect of CO2 on pH.

Dave.

 

[SuperColey1]

I agree wit Dave. Once I got my level and the drop checker was near to yellow I haven't touched the needle valve.

When I change the cylinder I don't even touch it. I close the regulator and then change cylinder then reopen the regulator. Needle Valve is already where I set it.

Andy