Stocking Question

[Jerry Sem]

My 60gal, well planted aquarium has been up and running for just over 5 weeks. It has ALWAYS tested (with API's Test Kit) ... 0ppm Ammonium/ 0ppm Nitrites and between 10ppm-20ppm Nitrates. I use Co-Op's EASY GREEN for my plants, dosing twice a week as instructed. My plant grouth is amazing. But (the big Butt), my HYDROCOTYLE TRIPARTITA JAPAN is just OK. It was suggested that my Nitrates might be a tad low for my plants and that my HYDROCOTYLE TRIPARTITA JAPAN might be deficient and to increase my Nitrate levels a bit. I have 11 (I bought 10 but an extra one snuck in the bug went the guy at the fish store, wasn't look'n) Zebra Danios. I believe their Bio Load or Bio Foot Print is very small, which probably explains my 0ppm Ammonium - 0ppm Nitrites and 10 to 20ppm Nitrates and holding, parameters. I was always planning to add Cardinal Tetras and Rummy Nose Tetras. I want to start with the Cardinals first. And now for my question (drum roll please) .... Would 12 be too much to add at once ? They're little buggers and I let them settle in for a few weeks before adding anything else. Eventully I would like a school of about 12-16 Cardinals and a school of about 12 Rummy Nose Tetras, to be added later of course. Thanx Jerry

PS I did add all 11 Zebras at once, with no issues in the water parameters and medium to heavy plantings.

 

[Byron]

The advice concerning nitrate levels is completely false. Most aquatic plants we keep in aquaria use ammonia/ammonium, not nitrate, as their source of nitrogen. There are very few that will prefer nitrate,. Walstad provides a list and Hydrocotyl umbellata is in the ammonium list, so H. tripartita probably is as well. Adding nitrates is not going to help plants, but it will detrimentally affect fish. Keep nitrates as low as possible; live plants (these help by rapidly using ammonia/ammonium and nitrite/nitrate does not result), water changes, clean filter, not overfeeding nor overstocking all help.

Hydrocotyl is a stem plant, and all stem plants are relatively fast growing plants, which means they need good (brighter) light than slow growers, and proportionally more nutrients. A photo of the tank would help in seeing the plants, but if you have many doing very well, they may be using, or be better/faster at using, the light and nutrients. Not all plants will thrive or even grow in the same aquarium.

The zero ammonia/ammonium has nothing to do with the fish but everything to do with the plants. I am going from your description, but if the plant growth is as good as you say, those plants are gobbling up ammonia as fast as they can. And plants are faster at assimilating ammonia/ammoniuum than the nitrifying bacteria. You coould add all the fish that tank can reasonably hold at one time and never see ammonia. Fast growing plants and surface plants are excellent for this, are literally "ammonia sinks."

As far as adding the mentioned fish, a group of 12 cardinal tetras is fine, as with all shoaling species add the entire intended group at the same time, they settle in much faster which avoids (or should) problems including ich. As for the rummynose, this species always fares much better the more ther are, and in this sized tank I woould not go below 20-25. They can go in all at once, and with the cardinals for that matter, assuming the plants are as you say.

 

[Jerry Sem]

Thanx Byron, All my Vallisneria Vals (37) plant are shooting out runners and one runner shot up my stone wall with 3 babies plants in tow. Looks pretty cool. Plenty of new growth too for them. All 4 Banana Plants have rooted and are shooting a new leaf each. In the past, never had much luck with Bananas, but so far so good. My Amazon Swords (7) are doing great too. They were nice sized when I got them.

 

[Byron]

Thanx Byron, All my Vallisneria Vals (37) plant are shooting out runners and one runner shot up my stone wall with 3 babies plants in tow. Looks pretty cool. Plenty of new growth too for them. All 4 Banana Plants have rooted and are shooting a new leaf each. In the past, never had much luck with Bananas, but so far so good. My Amazon Swords (7) are doing great too. They were nice sized when I got them.

Sounds like everything is OK. I would recommend substrate tabs for the Amazon swords, these are heavy feeders and substrate fertilizing does make a huge difference. The Seachem Flourish Tabs are good, I used them for over 12 years. The API are not anywhere near as good--or safe for that matter.

 

[Jerry Sem]

Will do ... Thanx again