Henning from Denmark - Please advice

Hi Affnan,

I am Henning from Denmark, but living in Indonesia I read your blog and it inspired me to try your Bell siphon design on my future system. I have a few questions I would really be grateful if you can answer for me.

First of all I am planning the following system:

Fishtank - 200cm x 150cm x 50cm= 1500L. This tank I plan to make out of wood with 5mm glass on the inside. I hope it will be big enough to fit about 100 tilapia.

The Waterpump is a Boyu PQ-1200 with 20w, 1260L/h, 1.8m maxhight
The airpump is Boyu U-9900 with 3.5w, pressure 0.012MPa, output 2x3.2L/min, will use 4 airstones.

Q1. Do I need some kind of filter for this setup?

Growbed - 500cm x 85cm x 35cm = 1487L. Will make this out of wood but with a plastic/rubber lining. Will use gravel size 10-15mm as grow media.

As mentioned I plan to use your bell siphon design. I have difficult finding the 25 to 50mm adapter :-( is it possible to use 1.25inch to 2inch instead? ofcourse it means all the other 25mm parts will be 1.25inch.

Q2. Do I need to make the bell bigger if the other parts are 1.25inch?

Q3. Is there anything missing in this setup?

Thanks a lot in advance.


Hi Henning

Q1. - Filter is an option, some say requires some say don't. With filter the grow bed may be a bit cleaner and easier to clean after one or two years of usage. I don't use filter any more.

The size that you specified is not a problem, make sure the adaptor has a funnel like reduction from 2" to 1.25" and not a square type of reducer otherwise it will not have the effect required for the siphon "Boost".

Q2. - The bell part of the siphon is not that critical, as long as you can find the right size to fit the 2" part of the stand pipe is OK, give some gap of roughly 1/2 inches between the 2" adapter to the bell inner diameter. Again this is recommended I've seen a much closer gap and its still work.

Q3. - That's about it in a basic system, if you have the grow bed on top of the tank its then much simpler, however if you place it further away, just ensure you have enough incline for the water flow. If the return to fish tank is long its is advisable if you could put a breather "T" somewhere along the path nearer to the grow bed.

On the number of Tilapia its should be ok, I normally recommend 1 fish per gallon maximum. I am sure you will not fill the tank to max height so the amount of water actually may be less that what calculated.

Hope you manage to set up your system.


No comments:

Post a Comment