M.C. Raúl Antonio Aguilar Castillejos writes...

Dear Mr. Goemans:

I wrote you a year ago (see below the letter) about the installation of a Freshwater plenum, and where you responded that I should remove the anti-dig mesh screen. I also made another change and used for the gravel 3 - 5 mm clay (In fact I use cat clay, without any additive of course). Do you remember?

"I'm going to start a new system with a 36''L x 15''H x 10''W aquarium. This will be a freshwater tank with 30 Paracherodon axelrodi and 4 Microgeophagus ramirezi and a lot of plants. I'll use a plenum as its main filtration system (I think I'll be the first in Mexico to use it in freshwater tanks). I can't find any reason not to use it in freshwater tanks, besides I think this is the way the rivers work in nature. I'm also going to document all the processes. I'll use 3 - 5 mm silica gravel for the plenum, and also use AZOO plant mixture. The layers in the plenum will be as follow: 1.75 inch for the first layer, then anti-dig mesh, then 1.25 inch for the second layer and finally .5 inch for the plant mixture. Could you tell me if these measurements for the layers and gravel are corrects? By the way, for the fish selection the temperature should be maintained high, but I read that the denitrifying bacteria might be affected. Is that correct?"

Let me bring you up to date: After a cycle stage of almost 3 weeks, I ran some tests and decided to start. The plants begins to grow and I add the fishes, calculate the quantity of feed, and everything begins to work exteremely well! It's actually fantastic!! The water is more than clean and everybody asks me how can I achieve that. Also it is about zero maintenance! Every month I clean the main Fluval internal filter, and after 6 months I change 25% of the water and clean the bottom just a little.

Every time I run some tests, the levels are almost 0. I think I must to publish this in order that all the freshwater aquarists know about it.

Thanks for your advice.

Regards

M.C. Raúl Antonio Aguilar Castillejos

Solutions Consultant

Vitria Technology, Inc.

Mexico, D.F.