Backyard Aquaponics
A place to discuss aquaponics

Hi All,I've been a regular stalker of this site for a few years now!, finally bit the bullet & bought a system (second hand) thanks Jason!I couldn't get a new system made for love nor money without payment up front & I wasn't going down that road, The system is supposed to be a bell siphon type but only one bed works properly the other 2 are all most flood & drain with me being the timer when I go out & lift the bells,( I think I need a higher flow pump from FT,which is 1600 x 500 x 1100 (880ltrs I think)
Grow beds measure 1200mm x 600 x 280, 3 off, the media is a mixture of blue metal & what appears to be ordinary 4mm fish tank gravel (aquarium type) What would the volume be taking into account the media, I get 606 ltr for the 3 combined but that's empty volume. I'm trying to prevent any problems from arising, as the Silver perch are nearly big enough & I'm looking for Barra silver lings next I've searched for ages & have got square eyes from bloomin 'puter. Any help greatly appreciated Also I think the pump I need should be capable of at least 1000ltr per hour correct?.Thanks Bj Da Bearr

I know a value of 1/3 water displacement is about right for hyrdoton. (i.e. 500L hyrdton will have 166L of water).

Just get a reasonable known volume sized container of gravel and weigh it, then fill with water and weigh and work out the weight of water (1kg = 1 L) if you need a more precise ratio for your gravel.

I'm not a full bottle on pumps - just know its advisable to turn over the entire FT volume every hour and that the pump rating is not generally given at its full head height, e.g a 1000L per hour pump may only do 500L per hour if pumping up to a head of 2m - need to look at specific data for a specific pump....

thanks for that!

Sounds like 2 of your beds are not getting enough flow. Turn on one of them at a time and see if they cycle like they are supposed to. You do have valves on each bed right?

yes I do! Yeah I think flow as well , I can get them to cycle individually but not all 3, like I said I think I need a bigger pump, I ordered the 1350ltr P/H job of BYAP on Friday, The fish tank is 880 ltr so should be more than big enough, I just cant figure out how big my grow beds are to work out the fish for next season,

Your 3 grow beds work out at about 600L... call it 500L because you wont fill them right to the top...

So 20 fish max IMO...

thanks all for replies, Yes I thought 20 would be max, cant eat the vegies fast enough so wont be adding more GB,Although might try a fruit tree in one bed I have spare ANy thoughts on best type of fruit will work Mango?

Lovely to meet you both on Saturday. I love to chatter on about AP ,probably more than i should, but oh so addictive isnt it!!

Hi S, yep could of stayed their for hours & so peaceful, with all the water trickling sounds ,Speaking of, I was talking to your colleague on Saturday & he convinced me to go flood & drain, I drilled the 2 holes in the stand pipe like he suggested, NOW all three beds bell siphon perfectly!! ( admittedly I connected the other pump also), But I forgot what was said about the timer I've got the pumps going for an hour at a time then off for 45mins, & they drain well empty, is that alright, I'm not to worried about conserving power for the moment just want it to work right.

15mins on and 45 off. Sounds like all is going well

will it hurt to leave the water pumping for 1 hr then off for 45mins? rather than 15 on 45 off? just thinking will pump full FT volume thru GB at least 3 times in the hr?

This is fine. The advantage of the drain cycle over simply running the pump 24/7 (I.e constant flood) is that you stir up the water in the grow bed (eliminating dead/low flow zones...if any) and get oxygen down to the roots in any of these dead zones. It "potentially" also helps drag some of the solids deeper into the growbed, rather than allowing it to accumulate on the top.

It doesn't matter what you have your cycles set up as really, as long as your water is well aerated when it enters the growbed. Hence why constant flood works just as well as flood and drain for the most part.

thanks all