I found this thread over at another forum pretty interesting. It was written by ray2828 over at arofanatics.com: http://www.arofanatics.com/forums/showthread.php?t=350581
After visits to se-ray-goon gardens by many ray hobbyists, one will have come across a very famous black ray breeder (p12, p13 and in time to come P14), Michael.
Like his doctor profession, his ponds are clinically clean, sometimes you catch a whiff of hospital smell, yes the ozone from the ozone generator. But what does the ozone really do for his rays and how they seem to breed like crazy?
Its conventional wisdom rays need good clean water. In ideal water conditions, an injured or sick ray will heal by itself. Needless to say then healthy rays are horny rays, one thing lead to another and 90 days later you get pups. At this point many a ray hobbyist will swear, my water is perfect what PH7, ammonia 0, nitrites 0 and nitrates <20ppm. What is wrong then? The answer lies in the ORP reading.
ORP stands for oxidation and reduction potential. In simple terms it is a measure of pollution. In a well conditioned pond you want oxidation reactions to occur, as they indicate the breakdown of water products. Therefore, the higher the ORP level, the less polluted the pond; the lower the ORP level, the more polluted the pond.
Low ORP levels can indicate low dissolved oxygen, high nitrites, or high Dissolved Organic Carbon (DOC), with the latter promoting the increase of harmful bacteria.
An ORP value below 200 mV will promote growth of slime algae, between 200 and 250 will promote blanket weed or stringy algae, and above 250 algae growth will be prevented. As ORP increases, the rate of healing of sick or injured ray increases and at high levels sickness (as manifest by not feeding) can be prevented. The table below summarises the effects of ORP bandwidth as a guide:
Readings:
< 150 mV --- Its somewhat like dirty drain water, significant improvements to the pond should be made as soon as possible to avoid rays being listless, not feeding and internal bacterial infections.
between 150 and 200 --- Ray health will be marginal. In pond environment, green water and slime algae a usual occurrence, especially in the absence of UV lights
between 200 and 250 --- Ray health will usually be okay, but not optimum. In pond environment stringy algae will normally be a problem.
between 250 and 400 --- Good to superb water quality, and prevention of fish health problems by excellent water quality control. The higher end of this range is preferred over the lower end for dependably good fish health and fast fish growth. Readings above 300 are preferred for healing sick rays.
between 400 and 450 --- Reflect the use of either potassium permanganate (PP) or ozone to increase water quality by addition of a chemical oxidant to the pond to oxidize the various dissolved organic compounds and solid waste materials on the pond bottoms and in the filter systems. Readings in this range usually do not harm the useful bacteria in biofilters if the length of time is less than 30 minutes in this range.
between 475 and 550 --- Reflect active potassium permanganate levels which should kill fish parasites without harming the fish, and quickly oxidize pollutants, provided the fish exposure is only a few hours per week. Water with ORP in this range should not be circulated in bio-filters since the useful bacteria may be oxidized significantly.
between 550 and 600 --- This is too high a reading and could lead to grill damage or organ damage in rays
Above 700 --- Kills all organic life form in 15 mins
Information above is extracted from article ORP as applied to Ponds by Dr Roddy Conrad, October 16, 2002.
Rays produces a lot of organic waste material. Our typical bio-filter is unable to breakdown all the DOC. In addition, the deployment of bio fliters typically lulls us into a sense of complacency, thinking all is well. Faced with such a situation, the deployment of ozone in the pond to raise ORP readings to between 250 and 400 is ideal for ray health and breeding.
Many of us do not have the luxury of an outdoor pond where ozone can be safely deployed. The following are some things that you can do to increase ORP:
i) Flow rates. The faster the better for higher ORP readings.
ii) Aeration, more the better.
iii) More efficient mechanical filtration, with frequent cleanouts or solid dumps, increase ORP readings.
iv) Temperature. Cooler temps will generally give a higher orp reading as there is a higher level of dissolved oxygen.
v) Fish load. Lower fish loads give higher ORP readings
vi) Heavy feeding gives lower ORP readings. More small feedings give less wasted food and higher ORP readings with better fish growth than fewer large feedings.
(v) & (vi) is essentially Boons method. Low density and feed little but fish in his pond grow to monster size.
vii) System Maintenance. Clean out filters. Back wash beads filter, rinse filter media in submerged filters.
viii) Find and eliminate dead spots in pond with low flow since this can accumulate solids wastes which lower ORP readings.
ix) Add bio-filtration capacity to increase ORP.
Well, the above seems to be a list of good fish keeping practices which everyone will claim they are already doing. Whats the catch? The simply answer is our rays are dirtier than we think. What we deem as sufficient bio filter capacity or cleaning regime may prove inadequate. What to do then?
 
The first step is to buy that ORP meter. Its a sort of system check to make sure that your setup is functioning properly. In addition, it will be an indicator to you when to change water and perform system maintenance when ORP dips. Or like Michael, you can deploy a n ozone generator.
Typically, emergency measures to raise ORP if your rays are sick include the following:
1) Introduction of PP and
2) Introduction of chlorine (so forget that de-chlorinator when changing water)
But remember, too high an ORP level also kills, that is why u need the ORP meter to monitor.
Happy ray keeping and Merry Christmas
After visits to se-ray-goon gardens by many ray hobbyists, one will have come across a very famous black ray breeder (p12, p13 and in time to come P14), Michael.
Like his doctor profession, his ponds are clinically clean, sometimes you catch a whiff of hospital smell, yes the ozone from the ozone generator. But what does the ozone really do for his rays and how they seem to breed like crazy?
Its conventional wisdom rays need good clean water. In ideal water conditions, an injured or sick ray will heal by itself. Needless to say then healthy rays are horny rays, one thing lead to another and 90 days later you get pups. At this point many a ray hobbyist will swear, my water is perfect what PH7, ammonia 0, nitrites 0 and nitrates <20ppm. What is wrong then? The answer lies in the ORP reading.
ORP stands for oxidation and reduction potential. In simple terms it is a measure of pollution. In a well conditioned pond you want oxidation reactions to occur, as they indicate the breakdown of water products. Therefore, the higher the ORP level, the less polluted the pond; the lower the ORP level, the more polluted the pond.
Low ORP levels can indicate low dissolved oxygen, high nitrites, or high Dissolved Organic Carbon (DOC), with the latter promoting the increase of harmful bacteria.
An ORP value below 200 mV will promote growth of slime algae, between 200 and 250 will promote blanket weed or stringy algae, and above 250 algae growth will be prevented. As ORP increases, the rate of healing of sick or injured ray increases and at high levels sickness (as manifest by not feeding) can be prevented. The table below summarises the effects of ORP bandwidth as a guide:
Readings:
< 150 mV --- Its somewhat like dirty drain water, significant improvements to the pond should be made as soon as possible to avoid rays being listless, not feeding and internal bacterial infections.
between 150 and 200 --- Ray health will be marginal. In pond environment, green water and slime algae a usual occurrence, especially in the absence of UV lights
between 200 and 250 --- Ray health will usually be okay, but not optimum. In pond environment stringy algae will normally be a problem.
between 250 and 400 --- Good to superb water quality, and prevention of fish health problems by excellent water quality control. The higher end of this range is preferred over the lower end for dependably good fish health and fast fish growth. Readings above 300 are preferred for healing sick rays.
between 400 and 450 --- Reflect the use of either potassium permanganate (PP) or ozone to increase water quality by addition of a chemical oxidant to the pond to oxidize the various dissolved organic compounds and solid waste materials on the pond bottoms and in the filter systems. Readings in this range usually do not harm the useful bacteria in biofilters if the length of time is less than 30 minutes in this range.
between 475 and 550 --- Reflect active potassium permanganate levels which should kill fish parasites without harming the fish, and quickly oxidize pollutants, provided the fish exposure is only a few hours per week. Water with ORP in this range should not be circulated in bio-filters since the useful bacteria may be oxidized significantly.
between 550 and 600 --- This is too high a reading and could lead to grill damage or organ damage in rays
Above 700 --- Kills all organic life form in 15 mins
Information above is extracted from article ORP as applied to Ponds by Dr Roddy Conrad, October 16, 2002.
Rays produces a lot of organic waste material. Our typical bio-filter is unable to breakdown all the DOC. In addition, the deployment of bio fliters typically lulls us into a sense of complacency, thinking all is well. Faced with such a situation, the deployment of ozone in the pond to raise ORP readings to between 250 and 400 is ideal for ray health and breeding.
Many of us do not have the luxury of an outdoor pond where ozone can be safely deployed. The following are some things that you can do to increase ORP:
i) Flow rates. The faster the better for higher ORP readings.
ii) Aeration, more the better.
iii) More efficient mechanical filtration, with frequent cleanouts or solid dumps, increase ORP readings.
iv) Temperature. Cooler temps will generally give a higher orp reading as there is a higher level of dissolved oxygen.
v) Fish load. Lower fish loads give higher ORP readings
vi) Heavy feeding gives lower ORP readings. More small feedings give less wasted food and higher ORP readings with better fish growth than fewer large feedings.
(v) & (vi) is essentially Boons method. Low density and feed little but fish in his pond grow to monster size.
vii) System Maintenance. Clean out filters. Back wash beads filter, rinse filter media in submerged filters.
viii) Find and eliminate dead spots in pond with low flow since this can accumulate solids wastes which lower ORP readings.
ix) Add bio-filtration capacity to increase ORP.
Well, the above seems to be a list of good fish keeping practices which everyone will claim they are already doing. Whats the catch? The simply answer is our rays are dirtier than we think. What we deem as sufficient bio filter capacity or cleaning regime may prove inadequate. What to do then?
 
The first step is to buy that ORP meter. Its a sort of system check to make sure that your setup is functioning properly. In addition, it will be an indicator to you when to change water and perform system maintenance when ORP dips. Or like Michael, you can deploy a n ozone generator.
Typically, emergency measures to raise ORP if your rays are sick include the following:
1) Introduction of PP and
2) Introduction of chlorine (so forget that de-chlorinator when changing water)
But remember, too high an ORP level also kills, that is why u need the ORP meter to monitor.
Happy ray keeping and Merry Christmas
