super_si

yeah i guess so. Any sites on stuff like this? Be interesting to read alittle about it

ajm

The best piranha site is http://www.piranha-fury.com (its American, so be warned )

There are some very knowledgeable people on there though.

David Lock

I can't quite understand heating problem. I am not fully conversant with your exact set-up but I would have thought that as soon as temperature rises slightly in sump then warmer water will rise and eventually full tank will be at optimum temperature? Is it possible that heaters are just being asked to work too hard and cut out before reaching temp? Looks great tank BTW. DL

Leslie

Looking good ajm.

Les

ajm

Basically the temperature in the sump rises (because that's where the heaters are) and the water is pumped into the main tank, cooler water from the main tank is displaced back into the sump.

If you had infinite flow (i.e. the two tanks were in fact one) then the temperature difference would be zero. However, the rate at which the warmer sump water can be pumped into the main tank is finite so there is a temperature difference between the two.

The nearer the temperature gets to the max temperature on the heater thermostats the more time they spend turned off (waiting for the surrounding water to be replaced by cooler water from the main tank), and consequentially the rate at which the temperature rises in the main tank goes down. So it takes exponentially longer to increase each degree of temperature, or at least that seems to be what is happening here.

ajm

Cheers Les!


Maybe I could sell tickets! "The Portishead Aquarium" - I like it!

PG

Looking good mate. Is that white sand you have there ?
How are you going to cycle the tank ?
Know what you mean about losing money on the tanks. Not to the same extent but I have Juwel tank I have for sale new was a daft amount of money and now for sale at about the cost of the stand and a couple of light tubes
I hope you arent thinking of changing the floor coverings in that room any time soon
ps. thanks for a high traffic thread to keep linking my tank too

ajm

Its normal aquarium sand (B&D Trading stuff). It looks very white in the photo due to the high UV content of the light tubes I have in there at the moment. I will probably opt for some cooler tubes as piranha aren't fans of excessivley bright lights!

Patt@firstime

Looks amazing mate, can't wait to see it with it's new residents inside as soon as I get my own place I will be doing a big tank but not this big. Fair play to you it looks

PG

ajm has 3 asylum seekers staying in the bottom of that and he pays them 75p per week to clean the sump out

Dave T-S

Except there is no diagonal bracing - and those little metal brackets don't count. Not being picky, but with 1.5 tons in there is a good chance it could fold up like a trodden on corn flake box

ajm

The sides provide adequate bracing from sheer forces (of which there are virtually none) and the wood is all positioned to accomodate compressive forces. I admit I'm no carpenter, hence the metal brackets and no fancy joints, but I do have a masters degree in mechanical engineering, and if my stand collapses "like a corn flake box" I will eat my proverbial hat! (once I have finished mopping up!)

tiggers

It really shouldn't need any diagonal bracing.

Unless ajm has the joinery ability of Helen Keller and the stand is nowhere near square then 99.9% of any forces on it will be compression forces and the sheer weight of the tank and water mean that any likely sheer forces applied to it (e.g. someone walking into it - there's Helen again ) will have absolutely no effect whatsoever.

Remember it's a static tank inside a house not a water tank on top of an exposed hill.

How's the temperature doing ajm?

tiggers.

ajm

Started at 17 degrees yesterday, now at 26.7.... only 0.3 degrees to go!

Dave T-S

I know it's compressive not shear (or sheer even ) forces, and the end panelling will prevent fore and aft movement, but there is no end to end bracing. A good shove on one end, particularly if you got the water moving, and it could easily go. I hope I am wrong, and not trying to poo poo a good project; as you say providing forces remain static and solely in compression it should be ok. But if it were me..........I would have diagonally braced it side to side

ajm

There is also a back to the stand made of 12mm ply which will brace against end-to-end sheAr ( ), trust me... it's going nowhere!

I do agree that cross bracing would create a stronger frame, but this frame was designed for a purpose, and in this instance stiffness against sheer forces had to be compromised to provide unihibited space underneath.

ajm

Well... we are cycling on/off bang on 27.0 degrees C, so the temperature problem is sorted!

Will let the tank run over this week to see if any other problems arise with a view to putting in the fish next weekend when I can spend some time keeping an eye on them! I'm not sure how "Lecter" the 10" ternetzi will take to his new smaller tankmates, so I want to be around in case of any trouble!!

tiggers

Good news on the temperature, but has it collapsed yet? Just kidding!!!

Hey Dave-TS - thanks for correcting my spelling of shear/sheer - attention to detail is normally my department - nice one.

BTW FWIW I would probably have stuck some diagonal bracing in - not because it needs it, but because I always over engineer everything

tiggers.

Dave T-S

Ah, you forgot to mention this ( or I forgot to read all of the thread )

Wasn't being pernickety re spelling, but same here

Re over engineering, the Colin Chapman approach is admirable (the car should be built lightly enough so it disintegrates one yard after it crosses the finishing line) but too scary a concept for me, so I tend to have a belt and braces approach too

ajm

The only thing that might be my undoing is the fish all deciding to swim up and down the tank at its natural frequency, creating a resonant wave with a wave length twice the length of the tank which would cause flooding, cyclic loading on my stand and possible catastrophic failure.

I wouldn't put it past the little buggers!

Leslie

I think you should have a tank warming party.

Les

David Lock

Bring a cossie

I thought you were going to post that thermostats had failed and tank was boiling this morning

ajm

Update:

The tank is still maintaining a steady 27 degrees C which is good news. I have some wood soaking to get the worst of the tannins out and will hopefully put that in by the end of the week.

I added a load of water conditioner on Saturday evening to remove the chloramine from the water (Bristol water use chloramine which is harder to get rid of than chlorine ). The conditioner uses sodium thiosulphate and the mechanism involves the liberation of small amounts of ammonia.

The water has responded to the removal of the disinfecting agent with a heterotrophic bacterial bloom and has gone cloudy. Hopefully this will run its course in the next few days because, although I am confident it is what I think it is, it always feels wrong to add fish to cloudy water!

In terms of managing the cycle, normally I use hardy fish like goldfish, but with a tank this size I would need a lot of goldfish, then would have nowhere to put them afterwards! I also thought about doing a fishless cycle but can't seem to find a trustworthy source of pure ammonia solution locally.

Therefore the plan is thus:

1) Move the fish in
2) Seed the new filter by placing bacteria rich biomedia from my other established filters in amongst the new biomedia - this should provide a good source of bacteria to start the culture in the new filter
3) Monitor the water parameters daily. If ammonia or nitrite levels get too high I will have to reduce it by water changes to prevent stress for the fish.

I am hoping that due to the amount of water in the tank, the levels will not spike dangerously high before the bacteria start to become established. Obviously it will be down to regular testing to make sure levels do not get very high, and if I DO have to intervene with water changes the only negative effects will be prelonging the cycle process. Its going to take several weeks anyway, so I'm in for the long haul whatever!

Leslie

Just shows how difficult it is to maintain what is a natural environment where they come from.

Les

prodriva

ajm, got an update for us?

You will definatly find the water parameters easier to cope with due to the massive volume of water your dealing with.

You mention the water has gone cloudy. This sounds like new tank syndrome where you just get a slight algeal bloom in the water. Have you got old/cycled filter media in you filter unit or is that all new too. You sound like an experienced fish keeper so assume you have some old filter media going on in the system somewhere. If you want to get rid of the bloom try a water additive or place a decent amount of polywhool in the filter which will polish the water to crystal clear.

Looking forward to some more pics

mj

I tried a water addative once to clear up a tank - next morning 6 dead discus fish

prodriva

Not surprising with Discus, they are very sensitive fish in general and any changes in the water parameters can cause havoc as in your case. Sorry to hear that matey Discus are very very nice fish.

mj

bit of a sickener, I had only had them a week, and there were still only babies - maybe 1.5 -2 inches long/round.

I wouldn't mind having them again, but they seem a bit of a handfull to keep, and I doubt they mix well with other fish.

David Lock

My pal sells live start-up bacteria for indoor tanks and outdoor ponds. About £7 for a small bottle, enough for 1000 gallons apparently. PM me if this is of interest and I will dig out his phone number. DL

prodriva

Discus are a bit misunderstood. They have been made out to be very difficult fish to keep. If they are wild caught specimens then they will be very sensitive to water chemistry. However most are bred by pro breeders and as such are not as sensitive to water parameters. If you have a good sized tank (3 foot+) and excellent filtration (external is the best option for Discus) then you should be fine with Discus. They do need very clean water hence why you need a good filtration system and you can easily buy additives that help to replicate the ideal water conditions for them (brackish IIRC) You also need to well cycled tank before introducing them to your tank. If you've got a good set-up give the Discus another go mj.