Art by Alexander Vasiljev, Copyright © 2017


Saturday, April 19, 2014


Tomorrow the fry will begin swimming around and I will be transferring them to a nursery. Due to my unique situation, having the pond in my apartment and no available space for any other water bearing container, I had to think hard and out of the box to come up with my set up. The basic idea is to keep the nursery tub suspended on two bamboo sticks above the main pond. The water will gently flow through the nursery tub into the pond.

I placed a small pump inside the UV chamber of the filter box (see my previous post on Filter Box Addition and Improvements) to divert some sterilized and ammonia/nitrite free water from the main pond into the nursery tub. I used 12 Qt (11.4 L) household tub, in which I cut out a slit for water overflow. This way the water depth will be constant at 4.5 in (11 cm). I covered the front of the slit with fine nylon mesh, glued to the walls with a 100% GE Clear Silicone I caulk and placed a filter sponge passed that to fill the slit.

Nursery tub suspended on two bamboo sticks above the main pond

Water hose delivers water from the UV chamber of the outside filter box

Water flow was further minimized with a drinking straw

Filter sponge is placed in the overflow slit to prevent any fry from escaping 

I payed attention to the strength of the water flow inside the nursery tub. The ranchu fry are not the best swimmers yet and can not fight any water current. So, in addition to lowering the pump's flow rate to a minimum of less than 30 gal/hr (114 L/hr), I inserted a drinking straw inside the ½ inch (1.3 cm) water hose to further reduce the flow to about 4 gal/hr (15 L/hr) or less. By lifting the straw up or down, I can control the flow. As the fry will be transferred into the nursery tomorrow, I will be watching closely the effects of this set up on their development. As always - observe, learn and improve.

If it all works, a huge benefit will be to not have to change water directly in the nursery tub, which disturbs fragile fry. Although, since I circulate the same water in the nursery tub and the main pond, my weekly 90% water changes in the main pond will be done regularly. Another positive outcome of this set up is a constant flow of clean and ammonia/nitrite free water that has just passed through bio-filter and UV chamber of the filter box.

I am certain, I will be making more modification to this set up as I learn more from little ranchu fry.