Fish space

[AquaDave]

What is the best rule-of-thumb for how many litres of water to cm of fish? And I mean the 1st one for growing space, and a second one for total space. I know fish need different requirements, but what for generally?

I have an Oranda (so could grow to 25cm I believe) and two Hong Kong Plecs (so 5cm each) and so how much space do they need? I will plan on growing lettuce and herbs out the top so that will deal with most of the fish's wastes.

And do any of you guys know where to buy a cheap lidless tank big enough for the fish? Thanks.

 

[Mebbid]

There isn't really a rule of thumb for most aquarium stocking aside from goldfish. It starts at 30g for the first goldfish and then an additional 10g for each additional fish.

That being said those two fish aren't particularly compatible. The hillstream loaches require very high flow whereas the gold fish don't need nearly as much.

 

[mrvincent]

There's no real rules, it's different for all species... Just goldfishs... They require lot more filtration...

AqAdvisor - Intelligent Freshwater Tropical Fish Aquarium Stocking Calculator and Aquarium Tank/Filter Advisor will tell you according to the adult fish sizes.

 

[AquaDave]

Thank you Mebbid and Mr Vincent.

Also, is that US gallons or British gallons?

 

[mrvincent]

1 Imperial gallon = 4.54609188 liters
1 US gallon = 3.78541178 liters

Here people usually talk about liters or US gallons.

AqAdvisor work in US gallons.

 

[AquaDave]

Would 100 litres be enough? That would have plants growing out of the top though so most of the nitrate would get used by the plants and thus taken out of the water - and any spare ammonium not turned into Nitrite by Nitrosomas bacteria would get used by the tank plants.

 

[Mebbid]

Would 100 litres be enough? That would have plants growing out of the top though so most of the nitrate would get used by the plants and thus taken out of the water - and any spare ammonium not turned into Nitrite by Nitrosomas bacteria would get used by the tank plants.

The plants will help but dont expect them to absorb all of the nitrate. You will still need to do regular water changes.

 

[mrvincent]

The plants will help but dont expect them to absorb all of the nitrate. You will still need to do regular water changes.

My tank is heavy planted with highlight + CO2 injection, and I can confirm nitrates build up overtime. I have a bit less nitrates than before I have put plants here, but still nitrate raising overtime.

Can't tell about phosphates, I think my API PO4 test is defective, I never got a reading over 0ppm with this...

Anyway, WC are required to maintain nutrients levels, there's some traces nutrients in the water that need to be renewed with WCs.

 

[AquaDave]

My pet 100L aquaponic tank will have only one resovoir of water, not two like in normal aquaponics. I got the idea from: Cheap and Easy $35 Aquaponics / Hydroponics Setup - YouTube and also kind of Back To the Roots AquaFarm, though not very much. It will have a massive airstone at the bottom with a good air pump and the bubbles will push water up, and top, filtered water back down. In his system (and mine probably) we'll be worried about not enough Nitrates because I'll be growing six lettuces (so 1-2 a week) and some strawberries and Basil. I will have a foam board attached to the top of the tank (not floating in water) with 12-14 netcups in and so can grow lots of plants as well as water wisteria and water sprite and java fern etc.

 

[Mebbid]

Regardless, you are still going to need water changes for a number of reasons. For reference on the amount of plant material this is an old picture of my tank. It is now WAY more overgrown than this. I still have nitrate issues with my tank.

Plants aren't going to pull all of the nitrate out of the water. This is going to be especially true if you aren't actively dosing fertilizers in the water. Assuming that you do a very very minimal amount of stocking, then sure it can help keep nitrates under control however nitrates are far from the only thing that we change our water for. You are still going to need regular tank maintenance.

Also, looking at the video I am 100% convinced that he is not an aquarist seriously looking at setting up a balanced system. His choice of water conditioner alone tips you off on that. The conditioner coupled with a fish load that would require a 60 gallon tank under normal stocking guidelines not counting the fact that those are likely common goldfish which will need a MUCH larger tank. When researching aquarium topics you really need to take the source into consideration and this is a prime example of that. So in short, don't expect miracles.

 

[AquaDave]

Yeah I've now got a 200L tank on the way and I will do my idea with aquaponics BUT you're right about him, he's a farmer not a fisherman so he knows almost nothing (but he did considerably well if you look at his other aquaponic videos - day 4, day 12 and week 4) and I only have an Oranda and the Plecs so there's plenty of space. I might add my 60 L HOB filter, my 21 L internal filter, as well as my (60 L) sponge filter I made (when I used medicine) to add lots of extra filtration, though I'll see if the tank does all right with just the plants first. I have a fish tank 5-in-one water test kit so I can easily test my water daily if i need to.

BTW thanks for all the input

 

[Mebbid]

I would highly suggest a liquid test kit over the 5 in 1 strips. You will also need an ammonia test which the strips don't have.

 

[AquaDave]

I would highly suggest a liquid test kit over the 5 in 1 strips. You will also need an ammonia test which the strips don't have.

My test is liquid but is 5-in-one. It has Ammonia, Nitrite, Nitrate, Ph, and High Ph but what I mean in 5-in-one is that they are all in the same kit together. Sorry about the confusion. API kit is what it's called.

 

[ScotJudd]

I agree with Mebbid. Test strips are quick but not accurate. Liquid test kits take longer but I can test ph, kh, gh , ammonia, nitrite and nitrate in under 10 minutes. Follow the instruction to the letter, especially for Nitrate testing.

 

[jwh0818]

My test is liquid but is 5-in-one. It has Ammonia, Nitrite, Nitrate, Ph, and High Ph but what I mean in 5-in-one is that they are all in the same kit together. Sorry about the confusion. API kit is what it's called.

Yes but I recommend getting an API master test kit, its liquid and doesn't give false readings like the paper strips

 

[Mebbid]

My test is liquid but is 5-in-one. It has Ammonia, Nitrite, Nitrate, Ph, and High Ph but what I mean in 5-in-one is that they are all in the same kit together. Sorry about the confusion. API kit is what it's called.

Ahh gotcha!

Usually 5 in 1 means strips that measure ph, nitrite, nitrate, kh, and gh. They are usually junk unless you buy the really really expensive scientific grade ones.

 

[tratcliffe44]

Rule of thumb that I use is one inch of fish for every gallon. After you do that then you can see about adding more fish if you have enough filtration but you would only want to add one or two fish at a time after get you take to one inch per gallon.
That's how I have always done it anyway. It works for me.

 

[jwh0818]

Rule of thumb that I use is one inch of fish for every gallon. After you do that then you can see about adding more fish if you have enough filtration but you would only want to add one or two fish at a time after get you take to one inch per gallon.
That's how I have always done it anyway. It works for me.

Do you take into account adult size when using this rule? Or do you take into account the bioload of each fish? Or the territory needs? The 1" per gallon rule was created to help petstores sell fish to unsuspecting people and for the most it works

 

[AquaDave]

I think that 200 litres is definitely enough for one Oranda and two Hong Kong Plecs! Also they'll have the lettuces, basil and strawberries as well as water plants.

 

[tratcliffe44]

Yes I use adult size for one inch of fish per gallon. When I start set up a tank I don't go over the 1 for 1. When you get more aggressive fish it is important to think about territory. But schooling fish it works good.
And I mostly stick to community fish.