Child’s first fish(es)

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otolith

55,899 posts

203 months

Monday 4th November 2019
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Thinking about it, this was a 40cm cube, so 64 litres, heavily planted with CO2 and LED lighting. I think I had 6 rainbowfish, 6 glass cats, 6 5-band barbs and couple of hill stream loaches in it. But the plants sucked up all the waste pretty quickly.

https://www.youtube.com/watch?v=Ugwv43K6P6Y

SeeFive

8,280 posts

232 months

Monday 4th November 2019
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Crossflow Kid said:
Am in reading that right?
You’ve got sixteen fish in the 45litre version of our tank? eek
Seems we’ve got a fair bit of spare capacity in that case.
Regards assistance with cleaning, there are three (out of an original five) cherry shrimps skulking around like sanitation ninjas. We did have a couple of snails too but they succumbed to the cold.
Yes you have got that right (well 14 small fish and 2 large shrimps) in 46 litres minus a little gravel and bogwood volume. Three of the fish are “helpers” and the rest are fairly light bioload as they have little bulk, more length (small bellies and bums) smile. Feeding is light but daily with auto feeders for when I am away, I don’t trust fish minders. No chemicals are ever needed or used except for water conditioner during water changes.

As suggested, one 12” fish will be unhappier than several little ones adding up to 12” in your tank but you have to increase stock slowly to let the tank biology increase to handle the additional outputs.

I would also have raised an eyebrow at my level of stock when I used to run bigger reef and fresh tanks years ago, but I have always kept a check on conditions in normal running and especially as new stock is added (very rare, they all live a long time) and over-filtered - more for failover than actual target turnover. For example, previously I had a moderate sized but deep one metre sea bray fish tank running two Fluval 406s across whole tank spray bars with another Fluval 106 tapped to very slow with an inline UV filter to kill protozoa, plus lots off pumped air to oxygenate the water. The reef tank was bigger with added filtration and power heads and stocked quite low for obvious reasons. Can’t remember the litres, but the filtration was designed to turn the tank over 10+ times an hour and never slowed at all between cleaning.

All new water was processed through slow RO filtration over a couple of days with salt and fresh minerals and trace elements added and measured respectively prior to water changes. 20% was changed each week, which was quite a lot of water across all the tanks and took a while to prep and execute !

Unsurprisingly I couldn’t keep plants alive (even with good light) as it was almost clinical but the fish were very happy which was my target. If you had suggested what I have today, I would have been very doubtful about the possibility of success and happy, healthy fish with good life expectancy.

Times move on and the hobby keeps getting improvements, but most still rely on old methods (e.g. fish out ammonia-based startups) and pessimistic measures of stock.

Today maintenance takes me about an hour a week to prep water and change for 2 tanks including a quick filter clean every other week, never cleaning both in each tank at once. All tests read zero except nitrate which is consistently about 20ppm prior to a water change but my ph is a little high due to living in a chalk area. As my LFS all use the same water source and I don’t have cichlids etc, I don’t really fuss about that reading too much.

otolith

55,899 posts

203 months

Monday 4th November 2019
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SeeFive said:
As suggested, one 12” fish will be unhappier than several little ones adding up to 12” in your tank but you have to increase stock slowly to let the tank biology increase to handle the additional outputs.
Just on the aquarist's rule of thumb relating to length of fish per gallon - the point above is very true. The thing that determines the consumption of oxygen and the excretion of CO2 and NH3 is weight, not length, and weight typically scales by something around the third power of length. The mass specific excretion/consumption rates are not constant for weight, 1kg of small fish excretes more and consumes more than 1kg of big fish, but the effect is not great enough to counteract the weight-length relationship.

If the exponent in the length weight relationship is 3, one 12 inch fish will weigh 144 times as much as twelve 1 inch fish. If you take the mass effect on excretion/consumption to be proportional to the mass to the power of 0.7 (values typically 0.6-0.8 depending on species and what you are measuring) you're still looking at your one 12 inch fish consuming 32 times as much oxygen and excreting 32 times as much ammonia as your twelve 1 inchers.



anonymous-user

Original Poster:

53 months

Wednesday 27th November 2019
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Here we are another month on and all is well.
Everything is much more stable, the live greenery is thriving to the point it needs pruning, the algal growth has subsided a bit and, the fish are happy as Larry.
There are occasional episodes of reclusiveness but a quick 25% water change and within an hour Marshmallow, Mushroom and Amber are out and about again.
What next though? Am thinking of adding a little more stock to keep it interesting.
Couple more platys or something else?

Sway

26,070 posts

193 months

Wednesday 27th November 2019
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That's great to hear.

I'm a big fan of corydoras - awesome little workers, sifting through the substrate, and great character too.

Many varieties stay pretty small, and they do best in groups. Perhaps five peppered/dwarf?

Turn7

23,502 posts

220 months

Wednesday 27th November 2019
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Yeah,I like Corys too.

Work well in that tank.

57Ford

3,937 posts

133 months

Wednesday 27th November 2019
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We've got 3 little Panda Corys which are great and always busying about cleaning up. We also have two small siamese algae eaters.
Our tank's a 64 litre so after a initial brief experiment with Platys ended in us being overrun, I gradually re-homed them and switched focus to only little types thinking of getting more movement and entertainment value. Endler Guppies are available in some really striking colours so we have some of those flitting round with a mixture of small neons and rasboras.

I also learnt the hard way that some really beautiful fish like Killifish and Apistogramma Agassizi are apparently peaceful but can be right bds!

paintman

7,669 posts

189 months

Wednesday 27th November 2019
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Perhaps avoid Panda corys, whilst being prettier then the others they do seem to be a bit on the delicate side.

essayer

9,011 posts

193 months

Wednesday 27th November 2019
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How did you rehome the platys?


I started with three of them five months ago, now there are at least 10 young eek

57Ford

3,937 posts

133 months

Wednesday 27th November 2019
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I have a mate who's a tropical addict - tanks in every corner of the house!! He has room for anything that doesn't suit my setup because he sells batches of stuff every so often. His largest tank provided hostelry for the violent ones too until the LFS opened to return them.

Caddyshack

10,605 posts

205 months

Wednesday 27th November 2019
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Glad to hear all is going well now

budgie smuggler

5,359 posts

158 months

Wednesday 27th November 2019
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Crossflow Kid said:
Here we are another month on and all is well.
Everything is much more stable, the live greenery is thriving to the point it needs pruning, the algal growth has subsided a bit and, the fish are happy as Larry.
There are occasional episodes of reclusiveness but a quick 25% water change and within an hour Marshmallow, Mushroom and Amber are out and about again.
What next though? Am thinking of adding a little more stock to keep it interesting.
Couple more platys or something else?
Good work but if the fish are becoming reclusive and a water change solves it, your filtration is inadequate or your water change routine is not regular enough.

I would resolve that first, otherwise you will be back to doing water changes every day.


Lazermilk

3,523 posts

80 months

Wednesday 27th November 2019
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57Ford said:
We've got 3 little Panda Corys which are great and always busying about cleaning up. We also have two small siamese algae eaters.
Our tank's a 64 litre so after a initial brief experiment with Platys ended in us being overrun, I gradually re-homed them and switched focus to only little types thinking of getting more movement and entertainment value. Endler Guppies are available in some really striking colours so we have some of those flitting round with a mixture of small neons and rasboras.

I also learnt the hard way that some really beautiful fish like Killifish and Apistogramma Agassizi are apparently peaceful but can be right bds!
Guppies are also live bearers though so keep that in mind, we got some and they soon started producing! Same problem with Platys now too, the babies are cute but often are eaten by the adult fish, so might stress your daughter out seeing this wink

LordGrover

33,531 posts

211 months

Wednesday 27th November 2019
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... or teach her the facts of life. :thubmup:

otolith

55,899 posts

203 months

Wednesday 27th November 2019
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LordGrover said:
... or teach her the facts of life. :thubmup:
If she eats her siblings, it's your fault.

anonymous-user

Original Poster:

53 months

Wednesday 27th November 2019
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budgie smuggler said:
Good work but if the fish are becoming reclusive and a water change solves it, your filtration is inadequate or your water change routine is not regular enough.

I would resolve that first, otherwise you will be back to doing water changes every day.
I’m talking a big change maybe once a week/every ten days.


Sway

26,070 posts

193 months

Wednesday 27th November 2019
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How much surface movement is there?

Might be they're responding to an increase in available oxygen for to the high gas exchange of water changes.

Might be worth adjusting the filter outputs to point up slightly and create more ripples - more ripples equals more oxygen.

anonymous-user

Original Poster:

53 months

Wednesday 27th November 2019
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Lots of ripples/bubbles.

otolith

55,899 posts

203 months

Wednesday 27th November 2019
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You probably want to be doing a small change that often anyway.

designforlife

3,734 posts

162 months

Wednesday 27th November 2019
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On my 60l tropical tank I had to do 20% water changes every 2 weeks to keep everything stable.