Water Quality * Controversial*

[Fredfish]

Danger! Danger! Will Robinson. Contorviersial post, do not read, do not zap ... gluurg ...

OK, I hesitate to post this because of the range of strong opinion it may raise, but I have gotten to wondering lately...

A lot of people, myself included, talk about keeping 'water quality' up. A recent post got me thinking exactly what that meant, and I must say, I don't quite know.

I, and most reefkeepers think about nitrates and phosphates when we talk about water quality. However, DanU, who has kept and raised many more seahorses than I, recently pointed out that nitates at 50 mg/l was high, but tolerable to horses (I hope I got that right Dan). I got excited two years ago when my tank hit 20 and a number of people at the time felt that this was getting to be too high for horses.

So, if seahorses tolerate high nitrates, what exactly constitutes poor water quality?

I would ask in advance that people posting here keep an open mind. There is bound to be disagreement and thats fine by me. Seahorse keeping is still in its infancy and we don't have all the answers yet.

Respectfully looking forward to your responses.

Fred

Note: in writing 50 mg/l of nitrate is tolerable to horses I am not suggesting that its a good thing to keep your nitrates at that level, just that it may not have the strong short term negative impact we think it will

 

[Samala]

Keep in mind this is a reef oriented message board, so we get reef oriented (coral oriented) posts and messages. Different water quality is good for different things. Coral happen to like very limited water quality conditions.. but not all aquatic life shuns 'higher' amounts of pollution in their water.

From an aquaculture perspective plenty of higher amounts of nutrients.. like that 50 ppm NO3, aren't terrible in a system that is raising seahorses and not attempting to also raise coral or other critters.

Heck from my aquaculture perspective seahorses are doing just fine in supplemented tanks where NO3 = 8ppm and PO4 = 0.1ppm. I feel that fish are much more prone to water quality issues when we have quickly toxic molecules like NO2 and NH3/4 in the mix, as well as other factors like pH, temperature, dissolved O2 and salinity. Those seem to have such a bigger immediate impact on our fish rather than NO3 / PO4 levels.

I think its great that you posted this though.

>Sarah

 

[Poniegirl]

As a keeper who has struggled with nitrate in the past (I have quit struggling and just stick to normal top off and WC schedule), I would agree with your friend Dan. I think much more damaging is the effort to control those 'trates and have a constant yoyo effect.
Mine stays between 20/40. The system has been established for 3 years and left to its own devices (with regular maintenance), seems to do fine.
I'm also glad to see this post.

 

[smpolyp]

I would say look at what where your organism came from. What are the water perameters there? For seahorses I would think nitrate is present and a must to help keep the plants alive. Although you have to say just because you can keep it alive does not mean it is healthy for you to do. Anyone live near some seahorses in the wild? If so test the nitrate levels for us please. You never know it may be lower than 50 or higher.

 

[Fredfish]

Sarah. Thanks for being the first to respond. I do understand that amonium and amonia can be very toxic, particularly at lower pH values. I always thought of them as a 'new tank' issue because once a tank has cycled sufficiently it will have a good bacterial population to process these compounds as they are produced.

With 3 seahorses and one Bangai in an 80 gallon system with lots of sandbed rocks and algae, I just don't worry about this. If you cut the system volume and biological filtration capacity by 3/4 to a 20 gallon tank, does amonia and amonium become an issue?

I also understand that rapid pH fluctuations can be very disruptive to organisms, but what exactly is a rapid pH fluctuation?

It is not unusual for our tanks to go from a daytime high of 8.4 down to 7.8. Dr. Schemik has suggested that this may also be normal on reefs.

I often wonder about disolved oxygen and what the effects are when it is low in a system. Late in the day in my system, you can actually see the algae bubbble off oxygen so I know my daytime oxygen levels are very good. But at night, with all the algae I have in the system, disolved oxygen is probably pretty low. This is also not unusual on reefs (and probably also in seagrass beds.

smpolyp. I do not believe that nitrates get anywhere near 20ppm on seagrass beds. All the nutrients in these environments tend to be bound in detritus and are used in the system as they are released into the water.

Back to nitrates. The reason I do not want them to get high in my system is that when some compounds are present in large amounts, they can interfere with the uptake of other compounds or can interfere with processes.

As an example, nitrates, if present in the boundry layer of fresh water plants at sufficiently high values, can interfere with the uptake of other compounds required for growth. This is something I read many years ago so I no longer remember the details, but the point is, excess nitrates can interfere with proper nutrient uptake in fresh water plants.

People can live in very poluted environments, but tend to be more at risk of a range of diseases and conditions depending on the polutants.

I wish I had more time and access to aquaculture resources. I really would like to understand fish physiology and biology better.

Fred