Koi Fish Information Centre

Nooura,
You need to make up your mind whether you will keep using the UGF or if you will go with an outside filter prior to breaking down the tank. I would argue for the outside filter.
If you follow that path, you will need several weeks to prepare for it. Get an outside filter, and start running it in your tank. Also get an air driven sponge filter and set it in the tank or another tank (better). You’ll need to run both for a few weeks to build up the bacteria you need for the cycle to occur with little or no disruption.
This next section deals with both ways: You should save as much of the water as possible. I see that you can save roughly 8 gallons right now, but more would be better.
Start by removing all your decorative material s in the tank–rocks, plants, bubbling sunken ships, whatever. Turn off your filters & heater. Siphon out some of the water into the buckets. If you have no other tank to move your fish–place them in the buckets, and cover the buckets so they do not jump out.
If you have more containers for the water, remove more water until you have only 4-5 gallons left in the tank. Remove the gravel, stirring it up to loosen the detritus that is in the gravel bed. Yes, the water will get really dirty, but you do not care about that right now. Despite what others have said in this thread, ALL of the substrate will have the nitro* bacteria living on the surface, not just the surface of the substrate. You WILL lose some during this process, but that cannot be avoided. Once you have removed as much of the gravel as you can, don’t worry about leaving some behind, and placed it in a container, or containers to keep it damp, You can remove the polyester. The polyester will also contain bacteria, and you will be losing those bacteria.
If you are going to remove the UGF, remove it. Place the gravel back into the tank, and, if needed, add more gravel to give you a good depth for your live plants, if you have any. Add about half the water you need, place your décor back in, add the fish and the rest of the water, and restart your equipment.
Sorry I am not going into it further, but my hand is still recovering and I think I am surpassing my typing limit for the day.
\Steve//

Category: Philippines Internet Koi Society