Backyard Aquaponics
A place to discuss aquaponics

I'd still go with the type of setup we have discussed previously - trickle feed to battery to inverter to pump. Means can source pumps at much more reasonable price and the run time would also be longer, particularly for a higher output pump.

Could dispense with inverter by using one of DC pumps mentionned by B2B earlier. This is what he was suggesting, i don't think it had anything to do with compressor and storage tank earlier discussion.

PS - I'm not sure a 10 litre per minute job would be sufficient for a heavilly stocked 2500l tank, particularly given that you may not really get 10litres when taking into account depth of airstone etc.

VB,

I think with air pumps flow is stated at just under .5 metres.

Depends what you mean by heavily stocked and a 2500 litre tank is going to have much more surface area for natural gas exchange than a 200L drum anyway

Don't forget, it doesn't have to be optimum dissolved O2, just enough to stop them dying.

Just posted it as an easy solution with out the stuffing around. Some people might get scared with sentances like
"trickle feed to battery to inverter to pump"

Steve - you are correct, the surface area of the 2,500l will be of reasonable size, but I expect in winter I would be coverring most of it with a lid of some type, so this might reduce the surface exchange of oxygen. Also, as you asy it is just a stop gap measure really for when the electricity is out.

Very true about the lid VB

I guess the only real quantative measurements would need a DO (dissolved oxygen) meter............ Am i that much of a techo-head that i'll pay $500+ for it? undecided. should i set up a poll?

I just came back inside from cutting the top off my 1000L tank.

I couldn't see what was going on down there.

So my heat loss will be greater now, but i'll have my heaters monday and i'll try and make a polystyrene lid tomorrow.

Smart me i dug it in so far from the shed that running an airline to it is not practical. I'll have to go to the "B" shop and buy a container that i can put all my electrical gear in with a lid that seals well. A few 20mm glands for the cables and i'll be good.

LB, what were the dimensions of the mini green house you bought?

slowly but surely

Dissolved Oxygen Saturation Limits for Water at Sea Level Pressure by Temperature:

F - (Celcius)
32 (0) degrees ...........................14.5 ppm
41 (5) degrees ...........................12.7 ppm
50 (10) degrees ...........................11.2 ppm
59 (15) degrees ...........................10.5 ppm
68 (20) degrees ............................9.8 ppm
77 (25) degrees ...........................8.25 ppm
86 (30) degrees ............................7.51 ppm
95 (35) degrees .............................6.8 ppm

DO requirements for fish and plants will vary as well. Anyone have the figures?

Silver and Jade perch can tolerate low levels (2 mg/l) for short periods (a few hours) but exposure to sub lethal levels (<3 mg/l) for extended periods will reduce growth and stress fish. 4 mg/l or greater encourage maximum growth.

With out a DO meter you will not know what your DO levels are.

Steve

just do your best to saturate, that is what I will be attempting to do!

The only kind of air pump I trust at the moment is the ELECTROMAGNETIC kind (DRIVEN BY ELECTRIC MAGNETIC MOTOR, ADOPT STRAIGHT LINE RECIPROCAL MOTION)... Look them up on ebay, `they are great and no worries about diaphragms as it does not have any!... they are just a bit pricey$$$ :confused3:

its what i use for my indoor tanks (ir pump type). i just go for the saturated approach there due to the stocking density! i'm figuring 30 litres per minute is saturated

hmmm, you think!


I have a 60l/min pump on my big tank with 5 airstones running 24/7 - if that does not saturate it then the powerhead with the venturi fitted shouyld do it! (it is only a 1200 L tank)

Its not so much the tank size than the O2 demand

I'd SOOOOOOOOOOOOOO love a DO meter so i can test the water return efficiency in my system. Its currently the only method i'm using. The pump is for inside

I only have about 40-50 tropicals in my tank, and a shmuck load of plants
those do meters are way EXPENSIVE!!!!!
Just checked up on ebay and they want AU $1,100.00 as a starting bid Guess I will lay off on getting one of those!

best i can get it for is around the $600 mark. Shhh say no more, as i'm on the edge.....................

you missed a spot...