Baptism Of Fire! Old Tank, New To Us.

[kennduffield]

We have a 33 gallon, 150 litre tropical freshwater tank. Currently at 26.4 degree C, Ph 7.6, ammonia 0.25 ppm, nitrite 0.0 ppm, nitrate 60-80 ppm. We bought the tank as a complete setup from a keen fish keeper that was moving on to a Malawi setup (whatever that may be).

The tank contains, 5 4cm angelfish, 7 3cm bronze corydoras, 1 8cm upside down catfish, and 1 7cm bloches catfish.

I know the nitrate is high, we have 40 ppm coming out of our taps! Currently using Nitrate Minus to reduce that. We have had the tank for 3 weeks now and the levels have been dropping to acceptable levels.

We are going to wait another week or 2 before we introduce more fish but I was wondering what fish to add to the setup. From the local aquatics shop we were looking at 3 3cm silver dollars, 1 4cm bristlenose plec and 1 4cm rainbow shark. These are all fish that he has in stock.

Are there any other fish you would recommend? We were possible thinking of a pictus, silver shark, cuckoo catfish. My wife is keen to get a bit more colour in there to offset the blue angels. I am looking for active, interesting fish.

The corydoras are a breeding group, as we have had eggs already, but the angels stripped all of them within 2 days. Whats the best way to try and raise fry? Can this be done within the main tank? The upsidedown and bloches are both shy beasts. I am presuming they are nocturnal.

Having been thrown in the deep end with this I am keen to do a proper job with these fish and keep them safe and happy.

Thanks for reading this, Kenn

 

[sadguppy]

Firstly, welcome to the forum and to the hobby! Both are very addictive!

The first thing you need to do is wait until the ammonia is stable at 0. Even 0.25ppm causes stress in fish and therefore daily water changes are a must - around 50% or more if you can. Perhaps you have a mini-cycle going on as a result of losing some bacteria during the move or maybe your tapwater has higher ammonia than the place you got it from, either way, no playing with the stocking until it stabilises!

Unfortunately your tank is pretty much fully stocked already for this size of tank. Angels are big fish once fully grown so you may want to pick a pair that get on, and get rid of the rest to another aquarist. You might then get away with a small group of shoaling fish such as tetra, as they have a small bio load, but not neons as the angels will eat them!

If you have your heart set on new fish, you need to rehome the existing ones however I really must warn your that your prefered species are not suitable. Silver dollars grow to a foot in diameter so they are out for all but the biggest setups and sharks need around four feet as a minimum tank size as they get aggressively territorial and need very robust tank mates - your angels are slow and have long fins and would be picked on relentlessly. Pictus catfish grow up to a foot and, like the synodontis (or cuckoo catfish) do far better in groups, so I am afraid they are out too.Have a look at the species index for more info.

For advice on spawning and raising cories there is a great cory section, however you do need to get to the eggs before the fish as they are just too tempting to eat!

 

[CezzaXV]

I would say you're throwing money away using nitrate minus. The best way to reduce nitrates is with a water change. 40ppm coming out of the tap isn't a big deal as most of us have some amount of nitrate in our tap water. Even the most sensitive fish won't be bothered by nitrate until you reach levels around 300ppm, not that you want to let it get that high. The guideline is to be doing large/frequent enough water changes that your nitrate doesn't go 20ppm above what comes out of your tap.

This thread here is what I posted when I got cory eggs unexpectedly and I was given some good advice. http/www.fishforums.net/index.php?/topic/391755-omg-cory-eggs/
The best thing to do is remove them and put them in a separate container or as you've discovered, they'll make a tasty meal for your other fish.

 

[Aqua Tom]

My Nitrate is 40ppm out of the tap, I dont worry about it.


Tom

 

[sadguppy]

Agreed. If you add live plants they use the nitrates as food so for planted tanks, nitrates are actually necessary. In your case, weekly changes of 20% should bring the levels down fine, once the ammonia is sorted out.