bio loads

[nitrous]

how can i tell if i have a good bio low or if its too high or low?

in my 20 gallon i have 4 black skirt tetras, 3 golden longfin danios a siamese algae eater and 2 red eye tetras. i think that is a medium or good bio load

55 gallon- 5 cories, 2 turqoise rainbows, 2 australian rainbows, britlenose pleco, 1 cae, 1 rainbow shark, 1 bala shark. i think that is medium also since that has a nice canister filter

also would i be able to add anything in my 55G, how about maybe 2 koi angels? are they agressive or peaceful?

thanks

[DeFeKt]

how can i tell if i have a good bio low or if its too high or low?

if your constantly fighting nitrates, mini cycles, ammonia poisoning and neglecting general aquarium maintenance, which is essential no matter how high your load is, your "bioload" is to high.

Ultimatly you can push the limits of your load if you are prepared to, or are already, doing more then regular maintenance on your conditions and water parametres.

I presume this is what you mean. hope it makes sense, and answers both your questions.

Matt.

[Lonewolfblue]

For the 20G, being mostly tetras, I'd say the lower end of medium bioload. Tetras are a low-bioload fish.

The 55G, medium to high bioload, as your bala will outgrow the tank, and when he starts getting big, you will see the water quality deteriate much quicker. But being that they grow kind of slow, took mine just over a year to go from 2 1/2 inches to 6 1/2 inches, you will probably have a year and a half to 2 years to find out what you are going to have to do with him. As for the angels, not sure. Haven't had angels yet myself.

Now remember this. This is if the tanks are fully cycled.

[rich311k]

The angels should be fine. They can get aggressive if they are a pair. Some can be nasty but most will do just fine. With the fish you have in the 55 you should be all right. As a matter of fact I think they will do nicely.

[BrianNY]

People often have the misimpression that filters are enough to handle the bioload of an aquarium that's pushing the limits. Cannisters are great for cultivating nitrifying bacteria. What one has to account for is that the more good bacteria in ones filter, the more nitrates produced.

[BillD]

Very good point, Brian. Adding filtration does not mean you can increase the bioload. The only practical way to deal with high bioload (assuming filtration is adequate) is to change water. Therein lies the problem with setting an arbitrary amount for water changes. The minimum amount of water that needs to be changed relies on the bioload of the tank, not some arbitrary number suggested by someone, as being adequate. If your nitrates are high, or climbing, you aren't changing enough water. adding more filtration will not change that.

[nitrous]

alright thanks for all the replies ill keep all this in mind and decide wether or not to add 2 angels or not