New Tank - Dying Ottos

Hi everyone,

I have a new tank (Fluval Roma 125 with Internal U3 Filter), setup in January with a fishless cycle done for about two weeks but also used a biological enhancer to speed up the process. One of my pals had 5 Serpae Tetras that he had in a seperate tank as they were nipping his Corys. So he gave me those to put in the tank as my first fish. After another 2 weeks i put in 6 Leopard Danios, 2 Pepper Corys and 2 Japonica Shrimp to see how the Tetras would deal with tankmates. Everything went fine. At this stage i was doing 50% water changes every weekend and everything was going well.

After another 2 weeks i added 4 otocinclus to aid in algae control from my plants. There wasnt an awful lot anyway but i read that they were a nice addition to a community planted tank. That weekend i done another water change and by the time i had finished an Otto was dead. I put it down to stress etc. A week later another had passed.

This time i let 3 weeks pass before adding more fish, 4 black mollys and 6 glass bloodfins. Again everyone was doing fine and my water tests were all normal. I decided to cross reference suggested temperature ranges, ph ranges etc to check that all my fish were compatible. It seemed they were but i decided to lower the temp from 26 degrees to 23/24 degrees. Again everything was going ok. In these 3 weeks i was doing a 25% water change every weekend.

Then yesterday i woke up to another dead Otto. Only 1 left from the 4 i put in and all the other fish doing fine. I'm just wondering if there is anything i have done wrong or should be doing to care for the ottos.

My water test readings from yesterday are: General Hardness: 60 ppm mg/L, Carbonate Hardness: 60 ppm mg/L, pH - 7.0, Nitrite - 0, Nitrate - 20, Temp: 23/24 degrees.

I have been feeding the fish twice a day, flakes in the morning and then pelles for mid water and bottom feeders in the evening.

Any help or advice would be warmly received.

AS Fiona said, otos are not really suitable for a new tank. If you have a lot of algae, you need to find the cause, but bear in mind that almost all tanks have some algae.
Excessive algae is caused by an imbalance of plant food (ammonia, nitrate and phosphate) lighting and carbon dioxide. How long are the lights on for as a first step?


I notice that you don't give a reading for ammonia - are you using strips to test with? You really need to know the ammonia level in the tank, so can I suggest you buy an ammonia tester and check that level.

Keep an eye on those serpaes, they can be very nippy if there aren't enough of them as your friend found. Leave enough space in your tank to get more if they do start nipping. They should be OK with at least 10.



You may find that you have problems with the mollies as time goes on. Your tests show that you have soft water and mollies tend not to well in soft water. You can confirm your test reading by looking for your hardness on your water companies website. If that confirms soft water, stick to fish that are OK in soft water - all the other fish you have are fine.

Just checked on my water companies website Sue, and it states my water is Slightly Hard. Hopefully will be ok for the Mollies. My friend that i got the Serpaes from has kept Mollies for a good while and hasnt had any problems and we live in the same town. Hope that bodes well for them - they're my faves!

Colly

If you have come across paddy c's cycling thread you'll see that he used a bottled bacteria product and mature media to kick start his fishless cycle, and he's still not finished.

Today is day 14 since adding Tetra Safestart and first full ammonia dose

The U3 is quite easy to tell - just have a look at the media. If they are horribly clogged with brown goo, yes it does need a clean. If they are brown but not horribly clogged, put them back and check again next week. You'll soon get to know how often to clean them. With the U3, the pads on the outside will get messy first.

Newly cycling filters are quite delicate - well the bacteria colonies are. It is better not to disturb them unduly. If the media are horribly clogged, squeeze the sponges and pads very gently in water you take during a water change; and just swoosh the container with the ceramic medium gently in the same water.


One of the best algae eaters is nerite snails, though the amanos you mentioned will also eat some algae. But make sure you have no trace of ammonia before getting any as snails are very sensitive to it. And nitrite.


I've just realised you have just 2 cories. They will do a lot better if you get 4 more of the same species