Oct 8, 2009, 2:08 AM
Post #25 of 33
The cockle/oyster shells act as a buffer to prevent pH crashes, so having NONE at all is not a good idea unless you use some other pH buffer additives.
Unless you have a fantastically designed and over-sized filter, I would say there would definitely be some level of sludge (dirt) in your filters. A good gauge is looking at the amount of sludge caking your jmats and other bio media. What you can see is probably only a small fraction of what is actually trapped in your filter. Actually if you ask for my opinion, midges are a good indication of how clean your filters are. If you open your filters and a cloud of them swarms out, you probably need to look at redesigning your filters or improving the maintenance. Midge babies (blood worms) feed on sludge and other rotting material, the more sludge (food) there is the more midges you will see. As we all know, sludge is not good. A lot of harmful bacteria thrives in sludge. You want as little in your system as possible, balanced by practicality of maintenance.
IHMO, you should always take 'professional advice' with a pinch of salt. I've heard this thing about not touching the filter media because all the good bacteria is inside. The professional also told me just backflushing weekly is good enough. I think a lot depends on your situation. If your filters are adequately sized for your bio-load and not caked in sludge, then that advice holds water. But I think many of us have over-stocked ponds and under-sized filters. When I used to blindly follow 'professional advice', my koi used to fall sick every now and then. I also had swarms of midges in my filters.
Then, I started reading forums and articles about koi keeping.
I have a tiny 5ton pond and a 2ton filter. I have 9 koi. I know I am overstocked and I cannot resist feeding them heavily. So I started developing my own maintenance schdule. I clean my first chamber weekly. I clean ALL chambers every 1-2 months depending on my feeding rate. I spray tap water through the mats and shells to dislodge most of the dirt. A lot of professionals and hobbyists will probably say I am crazy and killing my beneficial bacteria. Well, I have read about bacteria growth in koi filters and I believe that once the bacteria has colonized the filter, they are a lot more resilient than most people think. I used to religiously monitor water parameters before/after and in between all the cleaning. After I realised that my water parameters were ok and in fact improved after all this cleaning, I finally got lazy and only do occasional testing now. The cleaning is back-breaking, filthy and unpleasant. I could probably hire someone to do it but I think I would do it better and for free. I just take it as extra exercise now. Oh yeah, and I also try to do small water changes frequently. I still have a few midges around but at much lower levels and my koi have not been sick since (TOUCH WOOD!) .
I am not asking you to do what I do. Just saying to arm yourself with knowledge, observe your own situation, and make adjustments. Don't rely FULLY on professional advice. Remember that they might not be the best source of UNBIASED information. Only you yourself would have your own personal interests at heart 100%. Do not be mistaken that I am blasting all the professionals, I have had good experiences too with some like Max, NKF and mainland.
I think you answered your own question about whether you should clean your filters. Don't clean = midges, disease. I'm sorry but to me, if someone tells me to keep the sludge in my filters, I'd think its a load of BS!
Dear Bro Cookcpu,
Thank you so much for sharing your experience.
Will changing all the cockle shell (I only have cockle & oyster shell) cause any problem with maintaining my pH?
Can you recommend a good pond vacuum? I presume you remove your J-mat when u do yr vacuuming every week or two, do you? Was told not to touch the bio-media chambers by the person servicing my pond (just backflush those chambers will do but everytime I backflush I don't see the thick layer of dirt draining out. But I am sure they are in there, so maybe backflushing can't really get rid of the layer of dirt). So, always caught in this predicament because of conflicting info, clean -worry disturb the benefitial bacteria, don't clean - midges, disease..
Other than getting rid of the midges, do you see any benefits to the koi?
Sry for the endless questions.