Can planted tanks hold more fishes?

[yhbae]

I know live plants are helpful in aquariums. I have them in just about every aquarium I own. Never really thought of it much because it is a no-brainer unless species I keep eat them.

Since then, I started writing an online bioload calculator and tried to figure out what would be the effect of plants on the bioload. Many many people have been suggesting that I should add this "feature". Yes, plants do absorb _some_ toxic chemicals excreted by fishes, including ammonia and nitrates. On the other hand, I also read that fishes produce plenty more toxic chemicals/toxins that are not absorbed by plants.

So here's my ultimate question - can you keep more fishes in planted tanks? If so, WHY?

I always thought of having plants as a safety net rather than a mean to increase the total bioload of my tanks. But I would gladly stand corrected if this is not the case.

 

[emmanuelchavez]

In terms of bioload, they could theoretically hold more fish since due to the plants ability to absorb the nitrogen and phosphorous that fish and fish foods produce.

However, I wouldn't use that as an excuse to add more fish, since there are other factors to consider, such as compatability issues, and adult sizes vs. tank sizes. You can still have deaths and stunting due to overcrowding in a planted tank.

 

[OrangeCones]

I know live plants are helpful in aquariums. I have them in just about every aquarium I own. Never really thought of it much because it is a no-brainer unless species I keep eat them.

Since then, I started writing an online bioload calculator and tried to figure out what would be the effect of plants on the bioload. Many many people have been suggesting that I should add this "feature". Yes, plants do absorb _some_ toxic chemicals excreted by fishes, including ammonia and nitrates. On the other hand, I also read that fishes produce plenty more toxic chemicals/toxins that are not absorbed by plants.

So here's my ultimate question - can you keep more fishes in planted tanks? If so, WHY?

I always thought of having plants as a safety net rather than a mean to increase the total bioload of my tanks. But I would gladly stand corrected if this is not the case.

You can 'overstock' a tank if you have fast growing stem plants and/or floating plants, in my experience. To make it work, you need high light, fast growing plants and a good fertilizer schedule, including a good source of CO2 (either injected, DIY or soil based carbon).

Low-light plants will not allow you to over-stock. Anubias, ferns, mosses, etc. just do not grow fast enough to use the excess ammonia.

Most plants prefer ammonia. If ammonia is not available, they will convert nitrite to ammonia and use that. Last choice is nitrate, as it must be converted to nitrite then to ammonia.

I have several tanks with zero filters, just floating plants. I test the water parameters ever 2 weeks, and never see ammonia, nitrite or nitrate in them, even though they have dozens of fish.

 

[bmoraski]

I have several tanks with zero filters, just floating plants. I test the water parameters ever 2 weeks, and never see ammonia, nitrite or nitrate in them, even though they have dozens of fish.

That is really cool, i didnt know you could even go without filters.
thanks for that bit of info.