Moving water with Air.... Saving on heat and electricity

[Bitis]

Hi,

So on the recommendation of @clickme, I will show how I filter multiple tanks and "share" water and heat between tanks.

My reason for doing what I have done was based on a couple of factors.

1. Did not want to have heaters in every tank.

2. Wanted the ability to isolate a tank if required.

3. Same water conditions for a group of tanks, so that I could moves males or females around without ant stress.

4. Safe for fry.

5. Use of air as the main source for filters. 

6. Try and keep cost down.

The pictures below show what I have used and how it works. The U-bends are filled with water and as the level raises in one tank it flows to the next etc.

On my rearing bank I have a canister filter on tank one and then use the air to move water to tank 2,3 and 4 with one heater. Sponge filters on tank 2,3 and 4 prevent tiny fry from being sucked in, but I get the benefit of the canister filter from tank 1.

Any questions or ideas on how this can be improved or other uses, please add to this thread. @aquaholic99, contributed some good info on another thread, so if you could add it here, that would be great. Sponge filters from @The Tech Den, tubing from Bunnings and the pump is Aqua One Pond 02 - 8000

Cheers

[aquaoz]

@Bitis Do you find any difference in the water params by the time you get to tank 4? I assume with a canister on tank 1, that would be the cleanest.  But does temperature drop off towards tank 4? or do you get higher nitrates in tank 4?

[Bitis]

@aquaoz, Hi, as the tanks are not heavily stocked and each still has a sponge filter the water parameters are very good. The sponge filters actually move a fair amount of water. Temperature fluctuates by about 1 degree, depending on weather. But in Gold Coast cold is not really a issue, unlike Sydney. 

[The Tech Den]

I was wondering how you would go with a 30cm airbar - the reason for this is looking at the bear bottom tank it is getting a bit of buildup on it - although it would be easy to clean I am just wondering if the airbar at the back of the tank (or against one of the walls) would get a bit of current/flow from enough air that may keep it off the floor. Just an idea. 

[Bitis]

Hi, good idea. The tank that has build up on the bottom has Apisto with lots of fry, so I don't clean the bottom or siphon for a couple of weeks.

[clickme]

hi @Bitis some questions please

Quote

2. Wanted the ability to isolate a tank if required.

how is this achieved?  if you isolate one, how do you maintain flow to the others?

 

 

Q - why have both pvc siphon U bend style pipes and the water lift via air (sponge filters).  why not just the pvc, wont this keep the water level, level?  I am missing a principle here and can't put my finger on it.

Q - the sponge filters in each tank are for mechanical or chemical or both?  does the canister not do the whole job? or are you just playing safe?

Q - as a complete environment, all the tanks and canister together, what sort of water flow rate is happening and is each tank getting a good flow in and out?  Is this achieved because of the pvc, the sponge water lift type filters or a combination

[clickme]

hi @Bitis some questions please

Quote

2. Wanted the ability to isolate a tank if required.

how is this achieved?  if you isolate one, how do you maintain flow to the others?

 

 

Q - why have both pvc siphon U bend style pipes and the water lift via air (sponge filters).  why not just the pvc, wont this keep the water level, level?  I am missing a principle here and can't put my finger on it.

Q - the sponge filters in each tank are for mechanical or chemical or both?  does the canister not do the whole job? or are you just playing safe?

Q - as a complete environment, all the tanks and canister together, what sort of water flow rate is happening and is each tank getting a good flow in and out?  Is this achieved because of the pvc, the sponge water lift type filters or a combination

[HaydnRex]

@clickme the sponge filters move the water from tank 1 to tank 2 and the pvc water bridges return the water from tank 2 to tank 1. 

Without the air drivrn sponge the water wouldn't circulate. And without the water bridge the second tank would over flow as the first emptied. 

[Bitis]

33 minutes ago, clickme said:

hi @Bitis some questions please

how is this achieved?  if you isolate one, how do you maintain flow to the others?

Q - why have both pvc siphon U bend style pipes and the water lift via air (sponge filters).  why not just the pvc, wont this keep the water level, level?  I am missing a principle here and can't put my finger on it.

Q - the sponge filters in each tank are for mechanical or chemical or both?  does the canister not do the whole job? or are you just playing safe?

Q - as a complete environment, all the tanks and canister together, what sort of water flow rate is happening and is each tank getting a good flow in and out?  Is this achieved because of the pvc, the sponge water lift type filters or a combination

Isolation by removing the U bend and only using the sponge in that tank. If I want to continue circulating the other tanks under this system I could put in a long bridge, bypassing that tank and extend the clear pipe on one of the sponge filters.

Sponge is basic biological filtering.

Each tank gets a good flow, exact rate not measured. The flow is based on how much air you push and diameter of sponge outlet. You could just use a bent PVC pipe with a air stone and drive a fair amount of water. I used that method before when I had side filters built into the tank.

If you wanted, you could have the canister uptake in Tank1 and the outlet in Tank 10, no sponge filters and the U-bends would then equalize across all the tanks.

[clickme]

5 minutes ago, HaydnRex said:

@clickme the sponge filters move the water from tank 1 to tank 2 and the pvc water bridges return the water from tank 2 to tank 1. 

Without the air drivrn sponge the water wouldn't circulate. And without the water bridge the second tank would over flow as the first emptied. 

water bridge - thanks I will remember that.

that statement is logical.

 

[clickme]

6 minutes ago, Bitis said:

If you wanted, you could have the canister uptake in Tank1 and the outlet in Tank 10, no sponge filters and the U-bends would then equalize across all the tanks.

thanks for the answers and yes that also makes sense.

point of clarity.  If uptake was in 1 and outlet in 10 and water bridges only - would you still achieve movement/circulation of water or only 'level'.  for example if you were simply growing some plants but had no livestock, would you be able to achieve a minimal water flow with just water bridges.

[Bitis]

Yes, but dependent on the power / output of the canister filter.

[Slipshodman]

The trick with water bridges is that you must have a large enough bridge to deal with the flow required

So for the air driven system its spot on but you would need a lot bigger bridge to deal with the flow of a canister over the spread of tanks to ensure what you are pumping in has time to equalise the levels across all tanks 

Have messed around a little with water bridging  in the past ..... but hadn't thought about air driven set up like @Bitis has shared with us ... i like it 

[clickme]

35 minutes ago, Slipshodman said:

The trick with water bridges is that you must have a large enough bridge to deal with the flow required

sounds logical enough but I suspect it comes with experience.

I want to do exactly what Bitis has suggested in his hypothetical, but with a pump, as no filtration is required. 5 or 6 officeworks plastic containers, pump, water bridges. If I use 40ml PVC as per this advice, I should be able to set up something.  But I do like the air lift solution, lot less power, and suspect easier to tweak / maintain.

not sure if I should pump water in to the first as bitis has done and then waterbridge the lot. or pump to the lot and water bridge the lot.  logic and flow escape me, which is why I like what bitis has done and the commentry on this thread.

 

[HaydnRex]

You have to pump from the first into the last and water bridge the ones in between. 

If you have a pump in just the first tank there will be no circulation in the rest.@clickme

 

[clickme]

14 minutes ago, HaydnRex said:

You have to pump from the first into the last and water bridge the ones in between. 

If you have a pump in just the first tank there will be no circulation in the rest.@clickme

 

noice - thanks. that is bound to save some heartache.

[grigby]

Maybe a stupid question, but how do you initially activate the linking bridges i.e. remove the air lock in them and again after a 30% water change (for instance)?

[aquaholic99]

A quick easy water bridge can be made from any flexible hose and coat hanger wire (inside hose) bent  by hand for anyone wanting to experiment cheaply. The ribbed hoses do flow much slower than smooth hose though. Even a small air bubble will reduce efficiency. As will bristlenose cats.

If your worried, start off with clear vinyl hose so you can monitor everything easily. This isn't good long term though as clear hose gets algae (which produces air). If one bridge is too slow then use two bridges. However doubling the pipe diameter will quadruple the flow. 

 

The easiest way to remove air is with airline tube. Space the distance to the top of your bend on the outside, then slide the airline inside to the same distance. Then siphon water out of airline into a bucket, jiggling the airline back and forth 5 cm until no more air bubbles come through. 

[aquaholic99]

36 minutes ago, grigby said:

Maybe a stupid question, but how do you initially activate the linking bridges i.e. remove the air lock in them and again after a 30% water change (for instance)?

If you have longer legs on water bridge, you won't lose the prime when doing a water change. You will lower water on all inter connected tanks. The legs can go right to bottom of tank if you want to drain that much out.

[aquaholic99]

@Bitis The next evolutionary step is to bend your own PVC pipe. Elbows/joins are expensive, a potential leak point and terrible for friction. 

If you have a heat gun ($18) or gas cook top then your good to go. The trick is to heat slowly and much more area than you would expect. Keep the pipe from collapsing with a plumbers spring. I prefer filling the pipe with sand because that's what I'm used to but I'm sure there are other methods. Youtube will have plenty of examples I'm sure. 

 

I found a photo of U pipe bent with sand.

This particular piece is an emergency overflow on side of a sump - if the sump suddenly over fills (in a power outage) the pipe fills to create a siphon which drains much faster than gravity drain. 

 

 

Another example of bending pipe (I was in a hurry). This goes around the bottom of a central 100mm stand pipe/overflow and the water current prevents clogging. 

 

 

 

[grigby]

Thanks aquaholic99.  Will the same bridge principle work on a 2 tier tank with a canister filter supplying the water movement - inlet in bottom & outlet in top, with the bridge overflow pipe run between the 2 tanks: both pipe ends under water.  Will the bridge be self regulating via the flow of the canister to prevent overflow or is there a trick to it?  

[aquaholic99]

2 minutes ago, grigby said:

Thanks aquaholic99.  Will the same bridge principle work on a 2 tier tank with a canister filter supplying the water movement - inlet in bottom & outlet in top, with the bridge overflow pipe run between the 2 tanks: both pipe ends under water.  Will the bridge be self regulating via the flow of the canister to prevent overflow or is there a trick to it?  

Yes however water bridges connect horizontally and work by equilibrium.

Going from one level (tier) to another level requires an over flow. Look fairly similar but principles are fundamentally different.

I used 4 tiers and up to 50 2 foot tanks on one powerhead as this was the maximum lift of the pump.  

As someone mentioned earlier, it's easy to overwhelm a water bridge with a water pump. The best way to control this is with an adjustable bypass tap. Don't throttle the pump down, just divert excess water back into the same tank by opening up a tap on the low water side. 

The trick is to play until you get what you want. It's scalable and even used on commercial aquaculture farms. 

[grigby]

Thanks aquaholic99 you are obviously one smart & very experienced fellow.  Sounds like a brilliant idea and  well worth a try.  I will read your previous posts to find out more.

[clickme]

have to add my vote of thanks to all of you as well.  I have found this very valuable.

[Bitis]

Good to have these conversations and learn from each other. Thanks to all for their contributions.