bell siphon question

[litano]

I have tried 5 systems using bell siphon but have found I need to put a snorkel on each one. Without the snorkel, the system cycles inconsistently. I have seen snorkel less systems on the web that seem to work. Is it necessary?? thanks, lloyd

[TCLynx]

It all depends.  The breather tube is generally only needed in systems where the bell siphon is having trouble getting a good enough gulp of air to properly stop the siphon.  This is more likely to happen when there is a trap at the bottom of the siphon or a long pipe run on the drain end or an inflow rate to the bed that is almost too fast for the siphon.

[litano]

Hi, Thanks for the reply. Each system seems to have its own personality, so trial and error is what I have been doing. How important is the PH in aquaponics. I have a light to medium green color on the PH scale. I use PH Down on my hydroponic system, will that kill my gold fish? How about vinegar or lemon juice concentrate, thanks in advance.. Lloyd

TCLynx said:

It all depends.  The breather tube is generally only needed in systems where the bell siphon is having trouble getting a good enough gulp of air to properly stop the siphon.  This is more likely to happen when there is a trap at the bottom of the siphon or a long pipe run on the drain end or an inflow rate to the bed that is almost too fast for the siphon.

[TCLynx]

pH is pretty important, however you have to be more careful of how you try to adjust pH for aquaponics.

 

Aquaponics is a balance, the plants would prefer a lower pH while the bacteria want a higher pH and the fish want a medium to high pH.  The most common compromise range is between 6.5-7.2 ish.

Once a systems bio-filter is cycled up, it often naturally will bring the pH down depending on the media in the system and the source water's buffering capacity.  So it is often just fine to start an aquaponics system out with a pH between 7.0-8.0 and it will often come down naturally.  You need to make sure the pH doesn't drop too low because the bacteria can quit working and even die if the pH drops too low for too long.  I generally advise to take action to buffer the system's pH up if it drops below 6.5.  (6.0 is dangerous since some test kits only go to 6.0 and you have no way of knowing if the pH is actually way lower than that.  So I like to keep the pH high enough that you can tell it's above 6.0.)

You need to look at the ingredients in the hydroponic pH down Some pH down acids are safe for aquaponics, others are not.  Some have way too much ammonia in them and will overdose the system on ammonia.

 

Citric acid (lemon juice) and even vinegar to an extent have antibacterial properties and are not advisable for adjusting pH in an aquaponics system since we are trying to promote a bacteria based bio-filter.  Phosphoric acid and muratic acid are the most appropriate ones for initial adjustment of pH.  I have also used sulfuric acid for initial adjustment of tap water pH but one might want to avoid too much sulfur in a system so it isn't one I would suggest for regular use.

 

One should make sure that the media they use for aquaponics doesn't affect pH.  No amount of acid or pH down is going to help you if your media is limestone pea gravel.

[litano]

thank you so much for the detailed information. I am using 1/2 Hydroton and 1/2 stone pea gravel. I have lots of plants in my three systems that seem to be doing well.

TCLynx said:

pH is pretty important, however you have to be more careful of how you try to adjust pH for aquaponics.

 

Aquaponics is a balance, the plants would prefer a lower pH while the bacteria want a higher pH and the fish want a medium to high pH.  The most common compromise range is between 6.5-7.2 ish.

Once a systems bio-filter is cycled up, it often naturally will bring the pH down depending on the media in the system and the source water's buffering capacity.  So it is often just fine to start an aquaponics system out with a pH between 7.0-8.0 and it will often come down naturally.  You need to make sure the pH doesn't drop too low because the bacteria can quit working and even die if the pH drops too low for too long.  I generally advise to take action to buffer the system's pH up if it drops below 6.5.  (6.0 is dangerous since some test kits only go to 6.0 and you have no way of knowing if the pH is actually way lower than that.  So I like to keep the pH high enough that you can tell it's above 6.0.)

You need to look at the ingredients in the hydroponic pH down Some pH down acids are safe for aquaponics, others are not.  Some have way too much ammonia in them and will overdose the system on ammonia.

 

Citric acid (lemon juice) and even vinegar to an extent have antibacterial properties and are not advisable for adjusting pH in an aquaponics system since we are trying to promote a bacteria based bio-filter.  Phosphoric acid and muratic acid are the most appropriate ones for initial adjustment of pH.  I have also used sulfuric acid for initial adjustment of tap water pH but one might want to avoid too much sulfur in a system so it isn't one I would suggest for regular use.

 

One should make sure that the media they use for aquaponics doesn't affect pH.  No amount of acid or pH down is going to help you if your media is limestone pea gravel.

[TCLynx]

You said a light to medium green on the pH scale.  Now if you are talking about the regular range pH from the API freshwater master test kit then that is probably fine.  Just don't let it go yellow since if you get down to 6 it could actually be much lower and the ammonia could start spiking.

Most anything between green and bluegreen  on that test is good.

[Yusuf Mario Germino]

my affnan siphon is 100% reliable, it uses a reducer to create i think the bernoli effect of some sort... but anyway you can check his blog site

[litano]

Hi Yusuf, thanks for the reply. I used a reducer too but the bell siphon would not cut off consistently so I needed to install a snorkel on all of my 14 grow beds. It must be something with the dimensions of the components.

[Yusuf Mario Germino]

is the snorkel the air tube on top of the bell for breaking the siphon? yeah i have that as well, in all my siphons.  i love the sound of the burp!!!

actually i have super micro systems in my small balcony, 3 of them, i have i think 12 or so gallon fish tank made out of small water drum, and laundry tub as my grow bed that is not even 7"high.  been doing this since late jan this year, basil, okra, bell pepper are doing well but because they are outside (not directly under sun) , the heat i think stopped their growth, now i am converting my bedroom as indoor garden to put them all there, hopefully this weekend.... Jeddah Saudi Arabia's weather is difficult for some plants...

[David Waite]

Litano I use all bell siphons with no breather tubes. In my case if they shut off inconsistently I made the drain piping more verticle and used a longer pipe down to create more suction. Remember the longer the drain pipe  and the more verticle it is the more suction it creates which pulls harder therefore creating a cleaner break or loss of vaccum. Another issue I had was I didnt have enough holes in my guard at the lower end of the pipe. It restricted the water from tricking into the siphon and caused a strong sipping sound and caused unpredictable breaks in the siphon. Getting a siphon to start is usually a matter of more water flow and or turning the drain pipe elbow up a bit. Getting a siphon to shut off is usually the first in this discussion. There is a balancing act of water in vs drain. My siphons are 1 inch straight with no reducers and 2in bells over the top. All drain piping is 1in with 2 90s to control angle and flow.

[litano]

Thanks again. All of my systems are working well, but I will take your information into account when I build a new system. I am running out of yard room.

David Waite said:

Litano I use all bell siphons with no breather tubes. In my case if they shut off inconsistently I made the drain piping more verticle and used a longer pipe down to create more suction. Remember the longer the drain pipe  and the more verticle it is the more suction it creates which pulls harder therefore creating a cleaner break or loss of vaccum. Another issue I had was I didnt have enough holes in my guard at the lower end of the pipe. It restricted the water from tricking into the siphon and caused a strong sipping sound and caused unpredictable breaks in the siphon. Getting a siphon to start is usually a matter of more water flow and or turning the drain pipe elbow up a bit. Getting a siphon to shut off is usually the first in this discussion. There is a balancing act of water in vs drain. My siphons are 1 inch straight with no reducers and 2in bells over the top. All drain piping is 1in with 2 90s to control angle and flow.

[Ben Tamba]

Forgive me for butting in, but I need help and I am new to this forum. I am now building my aquaponics and I am experimenting with the bell siphon system. The siphon is 1" and 14" tall, and the bell is 2" and 16" all. It worked fine and the water was draining but then it stopped about half way through. What might be the problem? I will appreciate any advice.

[steve]

Hi Ben, Are your bell tops glued on? They can be tricky. Someday I have a plan to invent one that actually works.