Cloudy Water

Dear merx:

Your aquarium maintenance schedule is exemplary, but judging from the water chemistry readings you have reported, you may need to make some adjustments in your aquarium. Your pH, specific gravity, ammonia, nitrite and nitrate levels are all excellent, but your alkalinity is a bit high end your carbonate hardness is quite a bit higher than is desirable, and that may be why you are seeing some whitish precipitate in the aquarium water. (If it were due to a bacterial bloom, you wouldn’t be able to see small white particulate matter and strands with your naked eye.) The elevated alkalinity and KH should not be harmful to your seahorses in the short run, but you will need to take measures to gradually adjust them back into the normal range.

The easiest way to do this would be to make your water changes with RODI water that has not been buffered and is therefore soft. I would discontinue adding any buffer or calcium supplements until your alkalinity and carbonate hardness readings have dropped into the normal range indicated below.

Here is some additional information regarding the water quality parameters you should seek to maintain:

Basic Water Quality Parameters.

Ammonia (NH3/NH4+): Optimum level = 0 at all times

Ammonia is highly toxic to both fish and invertebrates in even small amounts (> 0.01 mg/L or ppm). Causes of ammonia toxicity include: immature biofilter (new tank syndrome), impairment of the biological filtration due to antibiotics and other medications, overfeeding, overstocking and dead specimens that go undetected (Webber, 2004).

Nitrite (N02): Optimum level = 0 at all times

Nitrite is slightly less poisonous to fishes than ammonia, but deadly to many invertebrates at very small concentrations (0.01 mg/L or ppm). Even trace amounts of nitrate such as this can wreak havoc in a reef tank and cause serious distress to fish. High levels of nitrite result from the same causes as ammonia.

Nitrate (N03): Optimum level = below 10 ppm in fish-only tanks; 0 ppm in reef tanks.

Nitrate is the end product of the process of nitrification, formed during the Nitrogen Cycle by the oxidation of nitrite by aerobic bacteria. Nitrate is relatively nontoxic to fishes, but elevated levels (> 20 ppm) are stressful to seahorses over the long term and promote the growth of nuisance algae. Reef invertebrates can be much more sensitive to nitrate, and concentrations as low as 0.06 mg/L can cause problems for symbiotic stony corals. The nitrate level is therefore a good indicator of water quality. For best results, consider using live rock and/or a live sand bed (preferably situated in your sump) in conjunction with a good protein skimmer to help filter your seahorse setup. The skimmer will remove excess organic compounds before they enter the nitrogen cycle, and live rock and a deep sand bed will provide significant denitrification ability, all of which will help keep your nitrates down. Don’t overstock, don’t overfed, remove leftovers promptly (a good cleanup crew is useful here), grow and harvest macroalgae, practice good aquarium maintenance and maintain a sensible schedule for water changes.

pH: Optimum level = 8.1 – 8.4 (typically fluctuates between 7.9 at night and 8.4 during the day)

The pH is a measurement of the alkalinity or acidity of aquarium water. A pH of 7 is considered to be "neutral," neither acid or alkaline, while pH levels above 7 are considered to be alkaline or "base," and pH levels below 7 are considered to be acidic. Marine aquaria need to maintain alkaline conditions at all times, and low pH (< 7.6) is especially detrimental to seahorses because it is conducive to Gas Bubble Disease. Normal daily fluctuations in pH are to be expected in the aquarium, and are generally gradual enough not to be stressful (Webber, 2004). Maintaining a sump or refugium with a reverse photoperiod to the main tank can eliminate these natural pH cycles. Regular partial water changes are the key to maintaining stable pH. Buffers can also help but the hobbyist should beware that excessive use of pH buffers may increase KH values to dangerously high levels.

Specific Gravity: Optimum level = 1.022 – 1.025

The specific gravity measures the density of a your aquarium water relative to the density of distilled water, and aquarists use it to estimate the salinity of their aquarium water (Trevor-Jones, Dec. 2002). In effect, it’s one way to measure the saltiness of your tank, since the more salt that is dissolved in the water, the denser it becomes. This can also be done by measuring the total amount of dissolved solids in the water, which is expressed as the salinity in parts per thousand (ppt). Hobbyists must remember that constant evaporation of freshwater from the aquarium causes the salts to become more concentrated, which increases the specific gravity or salinity accordingly. Therefore, it is necessary to top off the tank with freshwater regularly in order to make up for evaporation and maintain the desired specific gravity. Seahorses tolerate a wide range of salinity very well and hyposalinity (specific gravity at 1.011-1.015) is often used to help rid them of ectoparasites.

Dissolved Oxygen (02): Optimum level = 6 – 7 ppm

High levels of dissolved oxygen are vital to the well being of both fish and invertebrates. The key to maintaining high O2 levels in the aquarium is good circulation combined with surface agitation (Webber, 2004). Wet/dry trickle filters and protein skimmers facilitate efficient gas exchange and oxygenation. It is important for the hobbyist to monitor the dissolved oxygen levels in the aquarium because a drop in O2 levels is often an early indicator of impending trouble — a precursor of problems ahead. A drop in O2 levels will tip off the alert aquarist and allow corrective measures to be taken, nipping the problem in the bud before it adversely affects his seahorses.

Alkalinity: Optimum level = 2.4 milliequivalents per litre (meq/L), which is the alkalinity of natural seawater, is best for fish tanks; > 3.0 meq/L is recommend for reef tanks.

The alkalinity is basically a measure of the capability of your aquarium water to resist changes in pH from the addition of acid (Trevor-Jones, Nov. 2002). Acid is continually entering the aquarium, primarily as the result of respiration (CO2) and metabolic wastes produced by the aquarium inhabitants (Trevor-Jones, Nov. 2002). The addition of these acids tends to lower the pH of the aquarium water. The higher the alkalinity of your aquarium water, the more resistant it is to such downward pH shifts (Trevor-Jones, Nov. 2002). The amount of buffers (primarily carbonate and bicarbonate) in saltwater determines the alkalinity, so the alkalinity in effect is the buffering capacity (Trevor-Jones, Nov. 2002). When the buffering capacity of the water is depleted, the pH becomes unstable. Alkalinity test kits can now warn of low buffering levels in time to prevent potential pH problems (Trevor-Jones, Nov. 2002).

Carbonate Hardness (KH): Optimum level = 7dKH (the hardness of natural seawater)

Carbonate hardness is another measurement of alkalinity. It is usually expressed in the German unit dKH (degrees of carbonate hardness) and is often considered to be the total alkalinity. (Dividing dKH by 2.8 will give you the alkalinity in meq/L.) KH actually a measurement of various carbonates and bicarbonates of calcium and magnesium within the aquarium water (Webber, 2004). Maintaining a stable KH is very desirable since it maintains the buffering capacity (i.e., alkalinity) of the system and prevents subsequent drops in pH. Aside from stabilizing the pH, reef keepers need to maintain KH and high alkalinity in order to assure that the calcifying organisms in the tank flourish. Corals and other calcifying organisms actively use bicarbonate, which is the main component of alkalinity, so the alkalinity of a tank with a lot of calcification can drop quite rapidly.

Calcium (Ca): Optimum level = 350 – 400 ppm (up to 500 ppm in well-stocked reef tanks)

Calcium is a very important element in the water in any marine aquarium and is a vital element in reef tanks. Along with carbonates and bicarbonates, it is required by calcifying organisms such as stony corals, snails and other mollusks, coralline, Halimeda and other calcareous algae, and certain sponges (Trevor-Jones, Apr. 2003). Calcium reserves must therefore be replenished on a regular basis. Regular water changes may achieve this, but reef keepers may require the addition of biologically available calcium to maintain adequate levels (Trevor-Jones, Apr. 2003). Seahorse keepers should be aware that brooding males provide calcium to the developing fry in their pouches, which the embryos probably incorporate into their skeletons. Deficiencies in calcium could thus adversely affect your seahorses’ reproductive success and the health of the fry. In fact, seahorses that receive a diet deficient in calcium often suffer from decalcification of their exoskeleton, a debilitating condition commonly known as “soft plate” disease (Greco, 2004).

Phosphates (PO4): Optimum level = as low as possible in fish-only systems

High phosphate levels are detrimental to marine aquaria. In fish-only tanks, they promote excessive growth of nuisance algae, and in reef tanks they also directly inhibit calcification by corals and coralline algae (Holmes-Farley, 2002). Phosphates arrive in the aquarium in fish foods, through tap water, as an ingredient in low-quality carbon and marine salt mixes, and primarily through the waste products of the inhabitants (Webber, 2004). Phosphates can be removed by using commercial phosphate-binding agents, but growing and harvesting macroalgae and protein skimming are the best ways to reduce phosphate levels

Redox Potential or Oxidation Reduction Potential (ORP): Optimum level = 350 millivolts

The redox potential relates to the degree of water purity in the aquarium, and can be thought of as a measurement of the water’s ability to cleanse itself via oxidation. It is measured in millivolts of conductivity, a unit that provides information about the reduction and oxidation characteristics of the water. (“Redox” is merely a contraction of reduction-oxidation.) Oxidation-Reduction Potentials (ORP) are closely related to the stability of the marine aquarium and can therefore be used as a barometer of water quality. Highly efficient filtration, good aquarium maintenance and management, and the use of ozone in conjunction with a protein skimmer will help to boost redox values.

Seahorse keepers with fish-only systems need not be overly concerned about many of the parameters mentioned above, but I’ve summarized them anyway for the sake of thoroughness and the benefit of reefers who keep seahorses.

Aside from these basic water quality tests, I also recommend that you use a test kit for measuring the dissolved oxygen in your seahorse setup. The reason for this is that a drop in the level of dissolved oxygen is a great early warning indicator that something is amiss in the aquarium, and can thus predict potential problems (and allow you to take corrective measures) BEFORE they become full-fledged disasters. For example, a drop in O2 levels could be an early indicator of overcrowding — a signal that your system has reached its carrying capacity. Or it may merely signal a rise in the water temperature due to a summertime heat wave or indicate that the tank is overdue for a water change and/or a thorough cleaning to remove excess organics and accumulated detritus. Or it could be telling you that your tank is under circulated and you need to increase the surface agitation and water movement. On the other hand, it can also alert you to a potential gas supersaturation event, which can sometimes happen if a faulty intake or leak allows air to be entrained in a pump.

The point is that checking the O2 levels in your aquarium can alert you to impending problems and allow you to do something about them before they have dire consequences. A drop in O2 levels is often the first sign of a water quality problem and it can tip off the alert aquarist that trouble is brewing before his seahorses are gasping for air in obvious respiratory distress. Checking the dissolved oxygen levels regularly is the next best thing to continuously monitoring the Oxidation-Reduction Potential (ORP) or redox of the water, which is a luxury few hobbyists can afford.

It’s also possible for water changes to cause cloudiness and a whitish precipitate if the salt water is not mixed properly, merx. When mixing saltwater for your marine aquarium, it’s important to fill your container with all the water you will need BEFORE adding the salt mix. In other words, if you are mixing up 5 gallons of new saltwater, fill the mixing containing with 5 gallons of water and then add the salt. If you do it the other way around — dump the salt mix in the container and then start filling it with water, the water can become saturated with salt to the point that the calcium precipitates out. This calcium precipitation will turn the water milky and can also lower the pH to dangerous levels.

So be sure you mix your saltwater properly, use RO/DI water for your changes without buffering it until the alkalinity and carbonate hardness return to normal, and avoid adding buffers or calcium supplements for the time being, and you should gradually get back on track.

You should also be aware that 80°F is too warm for seahorses and can cause health problems for them due to heat stress in the long run. For best results, adjust your water temperature to 75°F. Seahorses typically do not tolerate temperature spikes to 80°F or above very well.

As you know, heat stress is extremely debilitating for seahorses and, in my experience, it is associated with more disease problems and mortalities in the home aquarium than any other factor. There are number of reasons for this. For one thing, elevated temperatures can have a very detrimental effect on the immune system of fishes. This is because many of the enzymes and proteins involved in their immune response are extremely temperature sensitive (Olin Feuerbacher, pers. com.). Some of these protective enzymes can be denatured and inactivated by an increase of just a few degrees in water temperature (Olin Feuerbacher, pers. com.). So when seahorses are kept at temperatures above their comfort zone, their immune system is compromised and they are unable to fend off diseases they would normally shrug off. It may not seem like a big deal, but raising the water temperature from 75° to 80°F can most definitely have a diverse impact on the long-term health of your seahorses.

At the same time heat stress is weakening the seahorse’s immune response, the elevated temperatures are increasing the growth rate of microbes and making disease organisms all the more deadly. Research indicates that temperature plays a major role in the regulation of virulence genes (Olin Feuerbacher, pers. com.). As the temperature increases, virulence genes are switched on, so microorganisms that are completely harmless at cooler temperatures suddenly become pathogenic once the water warms up past a certain point. Thus both the population and virulence of the pathogens are dramatically increased at higher temperatures (Olin Feuerbacher, pers. com.). Seahorses that are subject to heat stress are particularly vulnerable to tail rot and outbreaks of marine ulcer disease (vibriosis).

One simple way to drop the water temp in your aquarium is to position a small fan so it blows across the surface of the water continually (Giwojna, Oct. 2003). This will lower the water temperature several degrees via evaporative cooling (just be sure to top off the tank regularly to replace the water lost to evaporation). Leaving the cover/hood and light off on your seahorse tank in conjunction with evaporative cooling can make a surprising difference.

Here are some additional suggestions on cooling down your aquarium from Renée at the org that you may also find helpful:

Some summer tips are:

· Use computer fans (you can wire them to AC adapters… we are making some this weekend for our tanks).

· Use a big ol clip-on-fan or a fan on a stand that you can set close. (Just be mindful of water evap.)

· Float ice containers in the tank (Use water/liquid that you wouldn’t care if it sprung a leak. Those blue lunch/picnic type cooling things are not acceptable IMO…. what if it leaks? It will kill everything. I would recommend using bottled ice water because it will stay frozen even longer than fresh water….. but if you do use fresh water make sure it is water you wouldn’t mind spilling into the tank…. good ole tap water is not acceptable.)

· If you have a hood or canopy on the tank…..keep it off or lifted.

· Cool down the room the tank is in by using a portable or window AC unit. The window units can be pretty cheap.

· If the sun really heats up this room, look into some window tinting. This is what I did when I lived in South Texas. It dropped the room temp TEREMENDOUSLY! (If ya wanna go the cheap method, foil was used in many windows in the city I lived in… wasn’t the prettiest method but it saved many people lives who lived in places without central AC and couldn’t afford well working window units.)

· Shorten your photoperiod…. if possible don’t have the lights on in the hottest past of the day. But at any rate, shorten the amount of hours the lights are on for.

HTH
Renée

When reducing the water temperature via evaporative cooling, I should also caution you to observe all the usual precautions to prevent shocks and electrical accident when you are using an electric fan or any other electrical equipment on your aquarium, Chas.

One such precaution is to install an inexpensive titanium grounding probe in your aquariums. That will protect your seahorses and other wet pets from stray voltage and should also safeguard them electrocution in the event of a catastrophic heater failure or similar accident..

But the best way to protect you and your loved ones from electrical accidents around the fish room is to make sure all the outlets are equipped with Ground Fault Circuit Interrupters. And it’s a good idea to make sure all your electrical equipment is plugged into a surge protector as well to further protect your expensive pumps, filters, heaters, etc. from damage. Some good surge protectors, such as the Shock Busters, come with a GFCI built right into them so you can kill two birds with one stone. So when you set up your cooling fan(s) on the aquarium, be sure they’re plugged into a grounded outlet with a GFCI or a surge protector with GFCI protection.

In short, merx, you need to stabilize your water temperature at around 75°F and then gradually reduce the alkalinity and carbonate hardness of your aquarium as previously described. Your calcium levels are appropriate for a heavily stocked reef tank with lots of hard corals, but are higher than desirable for a seahorse setup which just has a few soft corals. Discontinue your calcium supplements and avoid adding any more buffer until your readings drop into the appropriate range for alkalinity and carbonate hardness.

Best wishes with all your fishes (and invertebrates), merx.

Respectfully,
Pete Giwojna

Dear Merx:

That’s a good dual phase buffer system by you’ll need to modify how you use it somewhat since its intended for use in reef tanks teeming with hard corals, Tridachia clams and other organisms that require higher alkalinity then fish only systems and and therefore need lots of bioavailable calcium. In a seahorse tank with lots of live rock and only a few hand selected soft corals, there isn’t going to be nearly as much demand for calcium, so you won’t need to use the dual phase buffer system nearly as regularly as you would in a full-blown reef tank. In your case, I would shoot for the low-end of the recommended range (i.e., alkalinity 3.0 and KH no more than 8.4). Once you have adjusted the alkalinity and carbonate hardness levels down to the appropriate level, you will probably only need to add the buffer once a week or whenever you make your routine partial water changes; you won’t need to add the buffer daily by any means. In the meantime, I wouldn’t add any more of the buffer at all until your readings come down.

Since your alkalinity and carbonate hardness are considerably higher than desirable for your particular setup right now, you may want to consider making partial water changes using unbuffered RO/DI water two or even three times a week until the readings come down to a more reasonable level.

Please do continue to take steps to lower the water temperature as well.

Best of luck working out the proper regimen for your dual phase buffer system so that it maintains the appropriate levels of alkalinity, carbonate hardness, and calcium for your seahorse setup, Merx.

Respectfully,
Pete Giwojna