Backyard Aquaponics
A place to discuss aquaponics

Once every few years we get snow for a day or few. It does often frost. Temps get down to 28F (50-70 daysF), but not for long. A greenhouse without heat or even a sheet is often enough. Winter is short.

Well, my tanks were back ordered and I am waiting for them to arrive. Do you think I should line my metal stock tanks?

I got a venturi pump today for the small tank my fish are currently in. I was impressed with then amount of super fine bubbles it blows into the water and its completely silent too.. I like this so much I think I will do this for my tanks instead of using air pumps! Also, I was looking at a protein skimmer the other day. I think that would be perfect to get as much oxygen into the water as possible. Not to remove organic waste, but just to add oxygen; does not work so well with fresh water anyway. I know there are fresh water models but I think they require high pressure. Would be neat to use a skimmer on the water returning to the fish tank dumping fresh water to the tank and returning the foamy organic waste to the grow bed.. Just a thought.. I will play with that some time down the road when I have the system up and running. Now back to the venturi pump. The skimmer model drew the air into the pumps blades to make super find bubbles instead of using a venturi. Would this work with a normal pump or would the cavitation destroy the pumps blades?

DanD..... the growbeds are both protein skimmers, solids removers and bio-filters..... three for the price of one

Think most people will agree that the water returning to your tank is so clean that IF you saw anything like a foam or a scum.... you'd be jumping into HSM.... coz something would be drastically wrong.

ok, not worth the effort then. I still think they would make great oxygenators.

What's a skimmer worth compared to a venturi pump

Dan

You got a link to the venturi pumps and the skimmer model? Cavitation is a problem on metal propellors (vaccum effect) but doubt it on new 'plastics' at the speed they are running. Its the speed of the propellor that produces the cavitation 'bubbles' not the introduced bubbles.
Re the skimmers, don't think you could get foam fractination(?) but may be interesting to reduce CO2 and increase DO. Is that a reverse flow model?

I don't have a link. I found a homemade fresh water pvc model online last night but I cant find it again; it was making foam. It was not a reverse flow model. Here is a home made skimmer on youtube

I was at petsmart the other night and I took one out of the box and was able to examine it before I got to many ugly looks from the people working there. It was just a submersible pump with an air line ran into the center point of the pump intake, a two chamber tube with the water coming in from the pump at an angle to make a cyclone. Looks simple to make. The box said the pumps blades mix the incoming air into super fine bubbles. Because of the cyclone effect the bubbles are in contact with the water for a longer time. Seems to me, that because I am going to need air this would be a great way to do it. Even a simple venturi and pump would work fine for O2. Just shoot it into a riser tube at an angle and let it flow out the top. If I can get a normal pump to suck air into it and bash the bubble into smaller bubbles that would be even better. Kinda like this Or this only as a cyclone. If am going to make one from a 12 volt marine pump. This way a power failure will not change the oxygen being input.

If I can use a high pressure pump then perhaps I could use this method before the bio filter on my breeders and fry tanks. This would save me the space for building large growbeds for them; just a small 50 gallon rubbermade stock tank with some heavy feeder plants in it. I want vegies on the large system, but it does not matter so much on the nursery system.

Ok, I found the
link to the home made fresh water version.

Dan

Have added the skimmer to my favourites (wish he'd put more pics of the construction). Second link to the vid looks as though he's using a powerhead, (neat idea) only problems I could see would be with that much air going through cooling may be a problem. When you say marine pump would that be one of the magnetic drive pumps? They are v expensive over here but I think can run with the impeller stuck (which means cooling may not be a problem).
Think its main advantage would be a degasser so it might be better after the bio filtration? If you get any gunge out of it personally I would not use it (think it would just keep going into suspension)?

Nice research Dan, new ideas are always good

Quick question. What about winters a grow beds? If the bacteria die at freezing then that means I would have to start over cycling my system every year, right?

Do you think I might place some of those electric pipe defroster strips in the bottom of the grow beds to keep them above freezing?

See that's the thing that confuses me...if the bacteria dies off at freezing, how come us folks in freezing climes don't have to have to re-innoculate all our rivers and lakes every spring? Or is it OK if the water is moving and therefore not freezing?

I think that's the key. By definition, moving water isn't frozen. Even when a river freezes it doesn't freeze all the way down.

Agree

Think you will find everything will slow down for the winter and with the gradual onset of spring and summer ie water temps rising bacteria will keep pace with the food supply. Cycling is mainly required due to using tap water which contains chlorine which kills bacteria and brand new systems which never had bacteria to start with. Of course if you up the bio load too quickly or overfeed when its not required you will still get spikes.
If you are worried about it a cheaper and prettier alternative would be to keep a coldwater fish in the house in a little fishtank with a small biofilter.
Or if TC's experiment works nix fish and just pee in it occasionally

I am still waiting on my tanks to arrive. I think the ag supply forgot to place my order; even though I already paid Anyway, I have two fish that are behaving like mails; picking a spot and defending it. I have separated the two male (I think) mossambicas and continue to wait for a male hornorum to show up. I took some time to examine the males privets and I think I need a magnifying glass, I cant tell anything.

I know for a fact that one of the two are males because he dug a pit and swims back and forth from his nest to where he can see the fish in the other tank then he raises his back fin all the way, puffs up his cheeks, makes a slow circle and returns to his nest. Very pretty being that he is orange and has stripes in his back fin.

The other one was claiming his spot and attacking all the other fish that came near. So I assume he is a male. His forehead was dark when I caught him and moved him. The darkness of his forehead got a lot lighter by the time I put him in the other tank.

I have cut their food back. Do female tilapia get aggressive and defend areas of a tank? Or is that always male behavior?

You have males. Females only get aggressive if they have a mouthful of eggs/larvae that need to be released soon.