Overstocked

[James9114]

If you read my sig you will see what fish i have in my rio 125 it is well matured and i have no water problems and do a 30-40 litre water change once a week every week. I know there is a lot of fish there but they have more than enough room in the tank and i never have water problems so is it all ok or am i heading for disaster? Remember none of my fish are big or get big which is why i think it will run fine but i'd like your suggestions.

Thanks James

 

[STEWARDSONS]

i would say you are about 150% stocked.

what filter do you have?

i am about 115% stocked on my 300ltr but i have a large external filter and a good internal, and i am just about borderline on filteration

 

[thisguyek]

I've been told it all depends on maintenance and filtration. as long as your tank is not overly 'crowded' per type of fish you have, then as long as you keep up one frequent water changes along with great filtration you can get away with much more than the 1" per gal rule. Any live plants? those help too!

 

[fluttermoth]

I think a useful guide to stocking levels is how fast your nitrate rises between water changes.

 

[Squidward]

I think a useful guide to stocking levels is how fast your nitrate rises between water changes.

I agree. If your filter is coping, and the nitrates don't get too high between water changes, you should be ok.

 

[This Younger Spouse]

I think a useful guide to stocking levels is how fast your nitrate rises between water changes.

Can you run me through the physics of this? I've read up on it a lot these last few months, but my thought would be that the ammonia from cast off food and lots and lots of fish urine would spike first?

 

[StandbySetting]

The Ammonia wont spike as there is a sufficiently big enough bacterial colony (Obviously it will have done at first, but the colony will have grown to cope with the waste).

From a personal view point I wouldn't say you're over stocked, but I wouldn't add any more fish, a weekly 25% water change should be a sufficient percentage to replace in order to keep nitrate under control, not that it is much of a problem anyway.

 

[fluttermoth]

I think a useful guide to stocking levels is how fast your nitrate rises between water changes.

Can you run me through the physics of this? I've read up on it a lot these last few months, but my thought would be that the ammonia from cast off food and lots and lots of fish urine would spike first?

Well, as SBS says, a good bacterial colony would deal with that, so you wouldn't neccessarily see rises or spikes in either ammonia or nitrite, but there's nothing that will process the nitrate. So if your tap water is, lets say, 20ppm nitrate that's your base level.

You'll probably have some in the tank, so lets say after a water change the nitrate is 30ppm.
If, before you do the next week's water change, the nitrate had climbed to 100, it would be sort of a 'red flag' that you were overstocked and you'd need to either reduce your stocking or do more frequent changes, because at that level of waste production in a tank, it would take only some small thing to tip the balance of your tank into allsorts of problems.

Don't forget there are sorts of undesirable things (like growth hormones from the fish) that we can't/don't test for that can build up in a tank and cause health problems/stunting, plus the more fish (and plants) you have the faster trace minerals get used up.

I know home nitrate tests are not that accurate; I'm talking about using it as a extra cheap and easy sort of 'barometer' of what level of stock and maintanence you should be looking at, no more than that.

 

[This Younger Spouse]

Well, as SBS says, a good bacterial colony would deal with that, so you wouldn't neccessarily see rises or spikes in either ammonia or nitrite, but there's nothing that will process the nitrate. So if your tap water is, lets say, 20ppm nitrate that's your base level.

You'll probably have some in the tank, so lets say after a water change the nitrate is 30ppm.
If, before you do the next week's water change, the nitrate had climbed to 100, it would be sort of a 'red flag' that you were overstocked and you'd need to either reduce your stocking or do more frequent changes, because at that level of waste production in a tank, it would take only some small thing to tip the balance of your tank into allsorts of problems.

Don't forget there are sorts of undesirable things (like growth hormones from the fish) that we can't/don't test for that can build up in a tank and cause health problems/stunting, plus the more fish (and plants) you have the faster trace minerals get used up.

I know home nitrate tests are not that accurate; I'm talking about using it as a extra cheap and easy sort of 'barometer' of what level of stock and maintanence you should be looking at, no more than that.

Thank you!