Backyard Aquaponics
A place to discuss aquaponics

EB - I get heaps of aeration in my setup also. Firstly, aeration of the sump as the water falls from the autosiphon and sucks air for a while at the end of the cycle before sipnon breaks. Secondly aeration from the venturi I have connected to the water inlet going into the fish tank.

KP - Easy to increase the size of my system - just add another $35 pump . If adding more grow-beds but not more tank volume (or fish density) then don't even have to add another pump, will just run longer cycles.

Been through all the headaches you describe in your "Pros" and "Cons" and know how you feel.

I ended in taking all the points and working on one at a time and slowly piecing it all together....I went on a different tack to most and eventually came up with a system to only flood one GB at a time...this reduced the size of the sump tank(s) required and allowed me to use a smaller pump.

Each direction has its own pros & cons (as you are finding out) - first point to consider is the size of the fish tank - no use having 10,000lph water flow in a 400 litre fish tank and have to work out a timing device for 30 seconds on and 50 minutes off (exaggerated but easier to see) - match the pump to the water volume



SO how big is your fish tank

Agreed - size of pump is relative to system.
Yours is cyclical yes?
I agree, so long as you have cyclical you can increase the cycle time.
If you have continuous you can't increase cycle time.

Multiple pumps doing the same thing offends my sense of neatness.
I will (future plans in consideration) probably add two more pumpos in various areas, BUT if I could do it with one, I would. As it turns out, I could but the problems with siphons over little fall and long distance have caused me grief.

I have 400mm fall, over 15 metres... in a 1" pipe, I get airlocks (probably because my trench wasn't 100% flat) If I had multiple small pumps this would not be such a problem. However a 100W pond pump from B @ $95 was unable to pump that head over that distance at anywhere near what gravity from 3m, and 30m distant can do. :-) provided of course airlocks are cleared.

I tried to explain this, mine is a unique setup, and my airlocks are perhaps due to bad design, but they are uncommon due to the distances involved and lay of my land. For this reason I have had to come up with a uniwue solution.

I still say though, cycle if you can, cos you never know what mistakes you might make.



I have 10,000L in my system at the moment, and am considering a 1000L sump upgrade

I'll give you one more guess KP

Perhaps your confusion relates to my references to cycle times. When I am talking about this I mean the time that it takes for the flood/drain cycle in a bed. This cycle depends on how quickly the beds are being filled by the pump/s and how quickly the autosiphons drain them (ie how big the siphons are).

As I said before - putting neatness aside of course - having multiple pumps and using autosiphons as I do means that if one pump stops the system keeps running. Any risk assesment will reveal pumps and switches as 2 of the major risks. With more than 1 continuously running pump then both these risks are coverred.

Regarding the head and flow - I am only pumping from the sump up into the fish tank (which is right next to sump - and gravity does the rest. The $35 pumps (3500 litres per hour - though more like 2500 at the head I have or less if venturi attached) are ample for the purpose.

Didn't you say you could increase the cycle time - this suggests cyclic...


Hmmmm redundancy... that is a pretty thing... neatness includes redundancy if it's done right...

I had thought I might need a new (bigger) pump perhaps it is just that I require two... hmmm...

You have given me much to think on master.

KP - I have edited my post while you were writing to explain what I meant when referring to cycling. See that post.

Sorry KP - I was still on answering Gemmell...hey!!! - no way, why am i apologising for - I am OT (on topic )

I have been repeatedly burnt by this because I have no backup (and no way to stop the flow at the other end). The power goes out, the pump in the sump doesn't turn on and I end up losing 500L (of a 1000L tank!). This is one of the reasons I'm re-doing my system as CHIFT PIST - reliability.



I did think of this, but I'm the opposite of KP - for me simplicity is the key - the more joins/bits/mechanics you have, the more chance of failure. And I'm a Software Engineer like him, so obvioulsy you can't stereotype us! (Well maybe if KP has geek humour and a nerdly laugh like me).



Would you mind putting the pumps you use in the pump thread for us? (link here for your convinence)

VB, you said you get good aeration, how does your pump do solids? Or are you doing it via venturi (and how is that working for you?). I suppose I should just read your bloody thread - been a while since you've updated it though. I just read the threads that come up under "New Posts" =).

"G", think there was some info on "solids" and "solids"

Solids such as stones, sticks, plant leaves etc are found in open ponds and are a problem for smaller pumps normally though they have some sort of cage to block larger items.

Solids in AP are normally of the excess food or fish poo and are usually "soft" and get mushed up in the impellers - so don't prove to be a factor (just gets pumped into the GBs and is dispersed)

With larger pumps and smaller fingerlings - normally the pump wins (fish scale confetti as Janet puts it )

So any solids experienced in normal AP systems can be easily dealt with by the smaller pumps - if you look at that thread with the pump info, both mine are listed and have been operating continuously since purchase - every couple of months I pull them out and give them a quick clean (but that is me - I also believe in running my power back-up system every month to make sure it works too )

agreed, just remove the sponge filter from the smaller pumps, it clogs quickly

LKB, thanks - it is really hard to retain all the information from all the threads, however I'm glad you've cleared that up for us. Tommorrow I start cutting down trees for my 2nd system!

By the way, that was exactly the kind of discussion I was looking for - good work team!

Yeah I have some trees to cut down for my system... Too bad they are my neighbors trees... Thats when you use copper nails... hehe

You will need to change your avatar picture, to yourself wielding and axe or a chainsaw...

Gemmell - I'll dig up some info on the pumps and post to that thread when I get a chance - but in the meantime, here is a link to the type of pumps I use (I amy have purchased some smaller and some bigger in the past, depends what is value for money) http://www.aquariumproducts.com.au/cata ... 7&catID=13

IMHO they are very reliable, although made in China.

Les has answered the solids question well, but remember that the pump is in the sump, not in the fish tank, so the main solids have been filtered out by the GB's before they get to the pump. Solids that build up in the sump are fine solids and where the pump is not they can be substantial (I have a build up about 10cm high in the sump at the moment, keep meaning to clean out and give to my soil garden plants.

Hey G, it depends on the volumes. I can't get an inexpensive timer that runs for less than 15 minutes, so a big pump is overkill. My system last year was a 100gallon/400L system that used a 100watt pump, which was way too big. The beds were full in seconds so the other 14 minutes of running were a waste. To me the reason to use a big(ger) pump on a timer is to move solids and flush things out for when the fish load is humming.

I plan to use a timer and a larger pump to remove solids to growbeds, but still use a small continuous pump going all the time to keep water moving for aeration and mixing, etc. You can get enough aeration from a small continuous setup if you make every transition produce waterfalls and bubbles. Like VB said you can easily add more flow with such a design - mine got another pump recently just for circulation and aeration purposes. It's not as cheap to add another large pump.

I made a small system outside with a small pump on a timer as well. This is an easy setup - three components, fish pond, pump on timer, bed draining back down to fish pond. The reason I chose to use a timer was because I didn't feel like figuring out the siphon arrangement for it, and I was going to be shutting it off at night.

The only problems I have had with the small continuous setup is that one pump died after a few months, and the flow rate changed from biofilm buildup in the hoses and so my siphons became erratic. Using PVC pipes instead of rubber and garden hose fixed the biofilm flow changes.

An interesting tid-bit. OT but does the biofilm not stick to the PVC pipes or did you use larger diamater PVC compared to the hose (the biofilm still builds up, but not enough to affect flow)?