[schildkoi]

Quote: Now in all my threads, you know that I absolutely positively state that if your going to have gravel - it has to be kept clean - or don't use it. I am consistant on this.

John, we both know that the owners of these ponds will not keep them clean. Anyone who thinks that they do is folling themselves. Even if the surface of the rocks looks clean the underlayers are not and thus maintenance most often is left undone.

Quote: It was also mentioned in this thread that stiring up gravel releases harmful gasses and organics into the water. Yes, you are correct - no arguement there. The AMOUNT of gasses and organics is extremely small and not harmful when cleaned on a monthly basis - 1/4 of the ponds' gravel every week. I am not talking about doing this to the "once a year cleaned ponds" of the Aquascape variety - I am talking about how aquariums are kept clean without harming the fish inside.

So now, 1/4 of the gravel has to be cleaned weekly? Do you honestly think that ANYONE will do this?

Quote: An additional method of protection could be the use of a pond vac for this type of gravel cleaning. "Fluff" the gravel with a water jet infront of the suction hose of a pond vac. The "soiled" water can be removed easily and not introduced into the pond at large.

So you are advocating the septic pumping once a week verses constantly flushing?

Quote: Once last comment was made regarding show quality koi and rocks & gravel. I am on redord as saying "I, and Russell Watergardens do not recomend koi that are to be grown and raised for the purpose of showing or competing be kept in any pond with objects that could cause physical harm as a result of collision - rocks includled." You have no arguement from me.

John, the actual comment was in referenced to family pets or show quality koi. BOTH deserve environemnts free of objects that could cause physical harm, don't you think?

And as for your conclusions regarding the surface area of rocks. Yes they can be calculated, but one forgets that only a portion of the top layer is exposed and less of the second and hardley any of the third layer. That and the fact that most water movements as you describe are surface and localized currents, let along the almost immediate fowling of any exposed gravel surface area to begin with. That in comparison to w Koi pond with TPRs, diffuser drains and smooth side surface area that is not only supplied constantly but also free of fowling debris and your arguement/logic here goes down the toilet so to speak. (pun intended) Now another factor you may not have considered is algae growth on your rocks at 3 ft of depth. This also inhibits the biofilm reducing such on your gravel immensly. On a Koi pond of depth, say 6', alge growth is inhibited and in many cases non existent and thus allowing for some biofilm. This is another reason why bio chambers are better left covered so as to reduce the algae potential on the media itself.

Steve