stocking Trigon 350

Nik_Boyd · Post by **Nik_Boyd** » 09 Apr 2005, 13:21

I'm getting a new Juwel Trigon 350 in about a month, and I'm starting to look into stocking and could do with some advice. The whole setup will be as follows -

Juwel Trigon 350lt corner tank, internal filter removed and bulbs changed for plant growing
Eheim 2128 thermofilter
TMC Vecton 25 (not for continous use, just to sort out any algae probs)
Co2 System, I haven't really looked into this yet, but getting advice on this from a good LFS

The tank is going to be live planted, and I'm aware that this could affect tank capacity, or ability to deal with waste loads, but I'll put more details in the plant forum.

The proposed starting occupants for the tank, after it has been fishless cycled are as follows -

L200, Ancistrinae sp.
Cardinal Tetra
Some varierty of Cory
a Male Betta

My problem is, I've no idea what the capacity of a 350lt tank is. Ideally, I'd like 3/4 L200's, but I'm aware they grow to over 7", a school of Cardinals and Corys, and the single Betta. Can anyone advise on numbers, preferably allowing for other fish to be added later. Also, can anyone advise on keeping Betta in a community tank? I've been told by several LFS that they can, but would like another oppinion.

cheers,

Nik.

MatsP · Post by **MatsP** » 11 Apr 2005, 12:31

The amount of fish that you can "safely" have depends on many different parameters, some of which are:
1. Water changing frequency and volume (i.e. 25% every other week will allow less fish than 50% every week).
2. Kind of fish. Some fish produce more waste, other fish tolerate more pollution, etc, need more or less oxygen in the water.
3. Filtration system.
4. Aeration. This is fundamentally an equation of surface area and water circulation. The bigger the surface area for the same volume, the more fish you can keep (except for "tall" fish, such as angels and discus, that requires a taller tank). Oxygen levels are also reduced by CO2 injection.

I'm not sure why you remove the internal filter. It may not be the greatest thing since sliced bread, but it's quite adequate as a starter. There's no reason why you can't have both that and the Eheim 2128. Or is it a cosmetic alteration?

A very basic rule is 1cm fish per 2 liter of water, or about 1 inch per gallon if you prefer non-metric measures. This is measured "Standard length", i.e. not counting the tail-fin, as the tail-fin doesn't usually contribute much to the waste a fish produces.

The Practical Fish Keeping web-site (http://www.practicalfishkeeping.co.uk, from memory, may be .com) has a "stocking calculator" where you can give the dimensions of the tank and it calculates the amount of fish you can keep.

As for your tank, I would think that 3-4 L200 would work just fine, as long as they have adequate hiding places.

A school of Cories will be just fine, as long as you're not planning the school to be bigger than say 8-10 of them.

A school of smaller tetras (cardinals, neons, glow, etc) of 20 or so would work just fine on top of this.

Betta Splendens should not pose a problem. They don't like really turbulent water, which the L200 would quite like, so you may have a small conflict of interest... But I think it's possible to find a good compromise here.

Heavy planting shouldn't reduce the amount of fish you can keep, rather the other way around. The plants will reduce the nitrate levels by using nitrate to aid their growth. Obviously, at some level, the plants will prevent bigger fish from having the swimming space they need, but other than that, it's fine.

Are you planning to use the fishless cycling described on this web-site, were you use dead shrimp or a piece of beef/meat for the cycling process? I'm sure it works, but it's probably safest to add some hardy/cheap fish to begin with, just to be safe, and as always, don't add ALL the new fish at once. There are several reasons for this, one of them being the shock to the filtration system. If you add a few fish at the time, you give the filter a chance to build up the good baceteria as you add the fish. If you add lots of fish at once, you will almost guarantee a spike in the ammonia/nitrite/nitrate levels, and quite possibly kill/harm some of the fish.

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Mats

Nik_Boyd · Post by **Nik_Boyd** » 11 Apr 2005, 15:49

thanks for your post mat, very useful. to answer questions that you reaised...

the filter is being changed for several reasons. The positioning of the filter in trigons is right at the back, and as the tank will be fitted in a corner, makes it pretty hard to get to. On top of this there is cosmetic improvement and space saved in the tank.

The fish will deffinately have a 25% water change every week, which could be upped to 50% if needed.

You say that adding CO2 lowers oxygen levels in a tank. Is this in any way balanced by the plant oxygen production? I'm going to cycle the tank using dilute ammonia, from a method on http://www.fishfourms.net and once cycled planning on adding the beta first, followed by tetra and then the bigger fish last.

thanks again,

Nik

MatsP · Post by **MatsP** » 11 Apr 2005, 16:15

Ok, to start from the back, so to speak: CO2 doesn't lower the oxygen content. I should have written that more clearly: The fish that need high oxygen content in water, also want's "low CO2 content in their blood". This is the same as with humans, CO2 content in the blood is controlling the breathing, rather than O2 content. So if CO2 is in higher content in the water, the fish needs to breathe more heavily. [Ever noticed how you start feeling tired and yawn when you sit in a room full of people. It's due to increased CO2 content in the air, you need to get more CO2 out of your body, and yawning is one way to increase your breathing]. So, no, it doesn't actually lower the O2 content, but it makes the fish need to breathe more rapidly, which isn't particularly good for them (at least if it's at extreme levels). Remember, these fish normally live in quite turbulent water with LOTS of oxygen, so they are not developed to sustain high CO2 content in their bloodstream.

Plants release oxygen, but it's debatable if that makes any distinct difference if you have relatively high circulation in the tank.

I've never heard of the "dilute ammonia" cycling of the tank. I'm sure someone has thought long and hard about that [and it makes sense, don't get me wrong], and if you're happy using that method, fine. I still think the traditional method of adding a few fish first is fine for me, I'm usually not that much in a hurry...

If you already have a betta in another tank, I'd also add as much water and perhaps also wash the filter media and/or add some gravel+water into the new tank, so as to boost the speed of the cycling.

I can see how the filter would be hard to get to. Didn't think about that (my filter is in the corner that is towards the outside on my Rio 400, which is really easy to get to, but I can certainly see how a trigon 350 would be a bit hard to get to...).

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Mats

Nik_Boyd · Post by **Nik_Boyd** » 11 Apr 2005, 20:26

thanks for the clarification on with C02

How would you suggest I control circulation in the tank? I'm assuming the spray bar from the filter will provide some, and the return from the UV filter, but is this enough for the plecs?

In theory, I haven't tested it yet but it seems plenty of people have, you can fully cycle a tank with no fish in it, cutting down on any stress caused to fish. Do you really think cycling a tank with a hardy fish causes it any real problems?

thanks for the info

Nik

MatsP · Post by **MatsP** » 12 Apr 2005, 10:32

Nik_Boyd wrote:thanks for the clarification on with C02

How would you suggest I control circulation in the tank? I'm assuming the spray bar from the filter will provide some, and the return from the UV filter, but is this enough for the plecs?

I've got the 1000l/h pump from the built in filter and a separate Eheim pump that does another 1000l/h in my RIO 400. The eheium pump cost about 20 quid at my LFS and is adjustable from 150 to 1000l/h, so you can adjust it a bit. It attaches to the glass with suckers like simple filters, and can be placed high or low, in any corner (or the middle) of the tank, just pumping water around. There are other models from the same and other companies, that do the same thing.

I also have a big airstone at the back of the tank, driven by a medium-large air-pump.

I don't think L200 is the most demanding when it comes to water current and oxygen levels.

Nik_Boyd wrote: In theory, I haven't tested it yet but it seems plenty of people have, you can fully cycle a tank with no fish in it, cutting down on any stress caused to fish. Do you really think cycling a tank with a hardy fish causes it any real problems?

I don't see any particular problem with the "non-fish" cycling, I'm just being traditional... However, my rosy barbs that I used for cycling the tank seem perfectly happy with their current existance in the now cycled tank, which took about 4 weeks. They spawned from the first month in the tank, and haven't stopped yet. Unfortunately, they eat their own eggs, and with about 12 other fish that also think fish-eggs are nice for breakfast, lunch or dinner, I doubt I'll find any more fry in the tank. I've fished out two fry, they are now about 2cm long, and saw another one that we couldn't catch before it 'disappeared'. Especially as I now have three in there, that will eat small fish if they get a chance...

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Mats