Total hardness (GH)MG/L over 300.

[wil-yuhm]

Hello,

Fifth week of new 66 gallon reef tank cycling at the moment. The water source I am using comes from our city irrigation system and not treated city water. The water is untreated from the Boise river. Testing the water in the tank a couple of times a week testable parameters are within range except for Total hardness (GH)mg/L. The test results in 300. At this point the tank at five weeks inhabits live sand mixed with dead sand/ dead rock/ added Purple and pink strains of coralline algae. For live stock around 10 janitors comprising of half hermit crabs and other half snails as well two clownfish. A young Mangrove tree also subsides. Should I be concerned about the "hardness" and if so is there any option/remedy besides going with a different water source (RODI) at this point? Lastly, I add a gallon of water or so every couple or few days from the irrigation water system to replace evaporation.

At this point I am only adding Reef Buffer 8.3 a couple of times a week.

Thanks in advance,
William

 

[Randy Holmes-Farley]

GH is not useful in seawater:

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com



GH (general hardness)

Hardness is a characteristic of water due to the presence of dissolved calcium and magnesium. Water hardness is responsible for most scale formation in pipes and water heaters (calcium and magnesium carbonates, typically), and forms insoluble solids when it reacts with soaps. Hardness is often expressed in grains per gallon, parts per million or milligrams per liter, all as calcium carbonate equivalents. It is a measure often used in freshwater aquarium systems, but not often in marine systems, where its values are very large. Seawater has a total (general) hardness of about 6.3 g/L (6,300 ppm) of calcium carbonate equivalents. These linked articles detail aspects of magnesiumand calcium in seawater.

 

[ReefEco]

While I understand you are looking for a non RODI solution, I will go out on a limb and suggest that your long term success with your tank will increase substantially if you get an RODI system. It is one of the cheapest and smartest investments in water quality for your tank. Who knows what may enter your river water before you can catch it with water tests - and unless you are doing full ICP testing of your river water on a regular basis whatever test kits you are using for "testable parameters" may not be catching the contaminants that could be a problem. Randy might also want to weigh in on the consistent use of 'reef buffer' ...

 

[gbru316]

The water quality in your tank will never be better than the water you mix your salt with. If you're already starting out with less-than-ideal water (nitrates, chemicals, medicine, ag runoff, etc), it's only going to get worse in your tank.

Of all the equipment that you can omit or "cheap out" on, an RO/DI is near the bottom of the list. The exception to this, IMO, is if you have a LFS that sells water nearby. But even then, what happens when you need to do an emergency water change at 10 pm on a Saturday evening?

 

[wil-yuhm]

Thank you for the informative responses. I'll order a RODI kit soon.