Backyard Aquaponics
A place to discuss aquaponics

hey all,

preparing for moving home, so i have to transfer my goldfish into a IBC tank, just wondering that for a full size IBC tank, can i fit 35-40 goldfishs? size varies from 25cm to 5cm, so have about 27 fishs for size 15cm up, the rest of them are about 5cm. Using a pump of 4000 litre per hour connected with a pond filter. will this ok?

Should be fine but pump is way overkill. IBC tanks usually hold about 1000L and you only need to flow 1-1.5x the amount of water in tank through the filter. I assume this is only short term? I would also add some aeration to the tank as well via air pump/air stones.

Yes it is temp solution for now to use that pump, later on I will change to my original 3000 l pump, by pumping to 1 metre height, the pump should be right size I reckon. And also I have add to air stone to help the oxygen.

Tell us about this "pond filter" - does it have enough surface area to handle all the fish waste without clogging up, and how does it remove nitrates?

It is a pond bucket filter that I bought from Bunnings few years ago, It had two layers of sponge then have a layer of bio ball

I wouldn't think that was enough for that many fish, although goldfish are quite hardy. You may have to do some periodic water changes to remove nitrates. I guess it depends on how long you plan on keeping them in the IBC.
Are you testing your water chemistry- pH, ammonia, nitrite, nitrate?

If it is for a short period (say 2-3 months) then you should be OK. Your biggest issue will be as the temps warm up. I doubt your filter will do much except get clogged up very rapidly.

Do you have media etc at moment ? If so get a blue barrel and fill it full of media (that you can use in your GB's later). That will be more effective than your filter. 3000 LPH is good, 4000 LPH will give a lot of excess flow so very unlikely you will have any aeration issues with goldfish as the excess water sprayed back in your tank from couple places from about 100mm would provide heaps of splash.

disclaimer- this is in answer to a 'temporary solution'. The longer you have it the more your issues will build up.
With goldfish you can feed once every 3 days or so and they will be fine, it will encourage them to graze on any algae.

and +1 to Guna - if you do that you must keep an eye on your water parameters and be prepared to switch out water regularly in reasonable amounts (50-100L per week) - use to water pot plants or something.

A better option would be to have 2 IBC's - are you planning on having a sump tank in the future setup ? That would get you 2 temporary FT's and bit more friendly for the number of fish you are talking about.

else - your smaller fish will do better in a crowded tank than the large ones - maybe consider selling the large ones - they will get you some cash pretty easily via Gumtree that you can reinvest later.

yes it is about 2-3 months i think, and i have just test the water, it seems all fine so far, but only have about 15 fishs now.

thanks, i was thinking to put some clay ball as filter media for this period, also, i am thinking to connected another IBC tank with the system, so more water volume, and may split the fish intwo different tanks.

currently i have all the fish stay in the pond, and pond connected with one ibc growing bed and two blue barrel growing beds, it was fine for few years now, after discussion, i think i'd better to do more safe method. will try to sell large comets on gumtree if i have that luck.

You can do away with the air pump if you put a spray bar from the pump outlet back into the IBC, spraying onto the water surface. Pumping for 3 minutes every 15 minutes will give a good aeration of the IBC.
Is it possible to connect up one or more of your GB's? That would overcome the ammo/nitrite/nitrate issues.

This is easily more manageable for Goldfish. If they don't look crowded and you just feed every now and again they will be fine. It was different when you were talking 30+ fish.

The pump will be heaps - you will get away with the 3000LPH and still have heaps of excess water for aeration.
That number goldfish would not need 24/7 aeration so don't stress too much about backup aeration (given Australia and any issue likely to be few hours).

Ultimately you need to look at how many litres per fish. For 15 fish you get 50-60L/fish which is very manageable.
Use a drum of media for a basic filter - that gets rid of the ammonia and nitrites which are main issue. Do some water changes when/if needed - use couple 20-25L white buckets. It takes a while for a 'fresh' system to build up levels - so you should be fine over 2-3 months.

was trying to make a thing to add more aeration.

i do not want to take too much risks, as i have them for years, so do not want to lose any of them. so if i use a bucket with 200 litre bio balls (the one from one ibc growing bed) to filter the water, as it is indoor, so there won't be any plants on that bio balls, does this sound ok to kill the ammonia and nitrites?

There is always a risk - and any move may result in the loss of fish.
When fish are moved it introduces stress, you also have new water conditions etc.
Irrespective of doing as much 'right' as you can.

Bio balls are plastic - I presume you are talking about expanded clay balls from the existing grow bed ?

Provided you keep feeding to a minimum and don't use growth feed, for 15 goldfish 200L of media as a filter should be enough to get the ammonia converted to nitrates. Nitrates are less of an issue for fish than ammonia or nitrites. If you have no plants then you need to do water changes. With nitrates in a system you do have a risk of algae.

keep in mind we are still talking temporary.
and you also need to pay attention to the water in your new location compared to your current water.

well, i already lost one large 20cm now, you are right, the stress may kill. i am thinking of sell some large ones to LFS, they are offering $10 each. as lease, it is better than to have lost.