Stocking level

[Jimfish98]

Curious as to thoughts on stocking level for a tank. The calculators just don't match the set up. I have 110g tank with 20g sump. Tank is bare bottom so no volume is consumed by plants, rock, etc. I am cycling water at about 700gph through felt rollers. I also have nearly half a cubic foot of Cermedia/Marine Pure in the sump. 

I am thinking of just going with a tank full of tetra, molly, platy, danio type of small fish. 

[Fish Folk]

On 4/8/2022 at 4:46 PM, Jimfish98 said:

Curious as to thoughts on stocking level for a tank. The calculators just don't match the set up. I have 110g tank with 20g sump. Tank is bare bottom so no volume is consumed by plants, rock, etc. I am cycling water at about 700gph through felt rollers. I also have nearly half a cubic foot of Cermedia/Marine Pure in the sump. 

I am thinking of just going with a tank full of tetra, molly, platy, danio type of small fish. 

Are you planning on any substrate? Plants? Hardscape? Just curious. Nitrate build up needs to be managed eventually if you've got a high stocking. Do you change water frequently?

[lefty o]

tank conditions, and level of acceptable maintenance dictate stocking levels. those stocking calculators or fish per gallon etc, are at best a suggestion to absolute beginners.

[PineSong]

A 110g setup for the fish you are talking about seems like heaven! I'd love to have a tank that size.

I think the answer depends on plants or no plants. I have a ton of plants in my tanks, and the calculators are very much erring on the side of safety if we are viewing safety as a low, slow, or nonexistant buildup of nitrates mandating water changes.

My livebearer/community tanks are usually "no" nitrates, occasionally will have the faintest coloration on a test strip, and that is with a number of fish that has gradually increased to 3x to 5x what a calculator would say is okay. The plants suck the nitrates right up. If I had messier fish or fewer plants, it would for sure require more water changes and lower stocking. I water change about 30% once or twice a month just to say I did it, not because of nitrates.

Of course there are other reasons to keep stocking low, like species requirements, aggression or aesthetics. But in terms of nitrates, I would say add fish gradually over weeks or months (after quarantining)  and when water changes are needed as often as you want to do them, stop adding fish. 

I'd like to get rid of my duckweed even if I had to do more water changes, but my other plants are worth their weight in gold by allowing leeway in how many fish there are.

 

 

[Patrick_G]

I think with that amount of bio media you’ll be able to pack it full of tetras, danios, livebearers etc. Like @Fish Folk mentioned you’ll need a way to get rid of nitrates, but plants and water changes should take care of that. If possible I’d suggest adding Hornwort or maybe floating plants to the sump. I understand from some commercial waste water studies that it’s the plant for Nitrate consumption, and it’s easy to grow. 

[nabokovfan87]

On 4/8/2022 at 2:14 PM, lefty o said:

tank conditions, and level of acceptable maintenance dictate stocking levels. those stocking calculators or fish per gallon etc, are at best a suggestion to absolute beginners.

Aq advisor is a very useful tool.

On 4/8/2022 at 3:43 PM, PineSong said:

I think the answer depends on plants or no plants. I have a ton of plants in my tanks, and the calculators are very much erring on the side of safety if we are viewing safety as a low, slow, or nonexistant buildup of nitrates mandating water changes.

For clarity sake, the key there being the last few words. You can stock a tank however you want with or without plants, the big reason we ask ourselves "is this ok" is because of the schedule to keep it healthy for the fish. Sure we want to make sure the tank is big enough, but you also want to just know that you're not changing water because of nitrates every few days.

Even if you're wanting a completely bare tank, you can pretty much always get away with anubias. There is a reason to have things in the tank, especially plants, depending on the stocking. Some fish lay on them, some want to break sight, some fish need a break to catch some more oxygen and just sit in the current.

Edited April 9, 2022 by nabokovfan87