Using activated carbon pellets.

[Spaceman]

I live in southwest Wisconsin. I have had the above described pond complete with rooted plants covering about 20% of the pond surface for about 15 years. About 5 years ago I had a major kill off and lost the 100 or more common goldfish that had been reproducing annually. I discarded the plants as they had gotten too large.
After draining and refilling with tap water last year I introduced 12 small common goldfish. We had a green pond within weeks. The filter I had been using the past 15 years deteriorated so there was no filtration last year. Two of the fish died. This spring I have 10 happy, healthy goldfish. The problem is light tea colored water.
I have removed the dead leaves from the past two years. There is little solid matter in the water. I also purchased and installed a new Fish Mate 15000P BIO filter. The system consists of, in sequence, a skimmer, pump, filter, waterfall (2 ft high) resulting in good aeration.
The filter has a tray to hold small ceramic cylinders called "SUPRA+". There is room in the tray for about 1/2 lb. of carbon pellets. There is a foam sponge that I presume will support the needed bacteria colony.
My question - Assuming 1/2 lb. of pellets, how often should I change the pellets?

 

[Lisak1]

The carbon will help with clearing that tea color from your pond, as long as the source of the discoloration is removed (most likely leaves, as you said). I don't know if there's a real scientific answer to your question as to how long that carbon will continue to be useful. I use bagged activated charcoal in my pond occasionally as the need arises. I would guess the bags weigh 1/2 pound each and I have four of them. My "strategy" (if you can call it that) is to use them until they don't seem to be helping anymore, then I replace them. I do pull them out every few weeks and rinse them off - I'm not sure if that helps, but it does clear away the accumulated algae which logic tells me means the water can flow through the bag easier.

So I guess I would suggest you just watch your water for signs it's clearing. You may find that once it's clear you don't need the charcoal anymore at all.

Any idea what caused your kill off? Have you posted pictures of your pond? We love pictures!

 

[MitchM]

Generally speaking, carbon should be changed out every 4 weeks or so.
It can vary depending on water quality and if the carbon is in an area of strong water flow.

 

[Meyer Jordan]

There are too many variables involved to quickly determine the use-life of AC in an aquatic environment.
Observed results or every 4 weeks as mentioned above by @MitchM and @Lisak1 would also be my advice.

 

[Spaceman]

I live in southwest Wisconsin. I have had the above described pond complete with rooted plants covering about 20% of the pond surface for about 15 years. About 5 years ago I had a major kill off and lost the 100 or more common goldfish that had been reproducing annually. I discarded the plants as they had gotten too large.
After draining and refilling with tap water last year I introduced 12 small common goldfish. We had a green pond within weeks. The filter I had been using the past 15 years deteriorated so there was no filtration last year. Two of the fish died. This spring I have 10 happy, healthy goldfish. The problem is light tea colored water.
I have removed the dead leaves from the past two years. There is little solid matter in the water. I also purchased and installed a new Fish Mate 15000P BIO filter. The system consists of, in sequence, a skimmer, pump, filter, waterfall (2 ft high) resulting in good aeration.
The filter has a tray to hold small ceramic cylinders called "SUPRA+". There is room in the tray for about 1/2 lb. of carbon pellets. There is a foam sponge that I presume will support the needed bacteria colony.
My question - Assuming 1/2 lb. of pellets, how often should I change the pellets?

 

[Spaceman]

More from Spaceman. I made two long thin bags from an onion bag because the mesh is quite small (1/8 inch). About a cup of carbon pellets would allow me to put the bag in the basket in the filter. I then put the other bag with four cups of pellets under the waterfall. I took a water sample this morning and can't see a difference from the original sample. I guess I need to be more patient.

 

[Spaceman]

I took a water sample today. On a scale of 1 - to - 10, it is down to number 91/2. More patience needed.

 

[Lisak1]

Yup, It's definitely a slow fix. But I have observed in our pond that it goes from level 10 to 0 very quickly. It just takes a bit to get started.

 

[Meyer Jordan]

Activated charcoal has the ability to adsorb many different compounds that may be found in pond water. Some possess a stronger ionic attraction than tannins. It may be that your activated charcoal is removing some of these compounds first. Once the adsorption of the tannins start it should be a fairly quick removal process as @Lisak1 mentioned.

 

[Mmathis]

What size is your pond?