Algae Identification/ RO/DI Question

[Otters]

Hello,

Well for the past 3-4 months I have been experiencing this aggravating problem with algae, I was originally using spring water to create the saltwater however I was told distilled water was even more clean of minerals. However the algae only reduced a little bit. I have 1 pecular clownfish, 1 tomato clownfish, 2 green chromis, 3 mexican turbo snails. The tank is 22 months old.

Water Stats:
pH-8.0
Nitrate- 5
Nitrite-0
Ammonia-0

Image of Tank: http://i203.photobucket.com/albums/a...o/felix132.jpg

I wanted to get a RO/DI unit however I was told that for a FOWLR it is good enough to have only a DI unit. If so does anyone have any suggestion to which DI provides the best result and if the algae will reduce in the tank.

[leebca]

Algae control is often one of the challenges in this hobby!

In general, like any lifeform, algae need nutrients. They use phosphates, nitrates, organics, carbon dioxide/oxygen, and light. The control is a multi step process that I would recommend:

1. Identify where the things it needs to live are coming from.
2. Starve the algae.
3. Physically remove it once 1. and 2. are in effect and been completed.

Staring with 1. you should test your water for phosphates and nitrates. See where they are at. Don't be too surprised to find them low, since the algae is probably consuming them.

Then, identify how these things are getting into the aquarium. Phosphates come from foods, organics, etc. Nitrates come through wastes, organics, etc. Suspecting your source water is good. Test the source water. Don't starve your fish, but remove uneaten food and foods that are caught up in any filter. You should be using a mechanical filter of some sort -- keep it cleaned out and put it on a daily maintenance.

2. Once identified, remove the excess nutrient sources. Use a skimmer to control organics AND activated carbon. Perform more frequent and larger water changes with source water you are sure about. (Forget about cutting down on lighting -- Mother Nature can find something to grow even under low lighting). Check the kind of lighting you use -- some plants like or prefer certain wave lengths. Changing the kind of lighting might reduce some growth. Another thing to consider is to setup a refugium (a small hang-on would do) to actually grow algae. This then competes with the algae in the display for nutrients and further reduces them in the water. Add many algae-eating snails. They won't eat mature algae, but once you do 3. they will keep it cropped. Lastly, you can get real nasty to the algae and add on chemical filters. You could add on a chemical filter that absorbs phosphates.

3. Now properly prepared, physically remove all the algae from the display rocks -- right down to the bare rock!

Your question about DI water is partly true. For FOWLR DI water is usually good enough quality. BUT DI water is only as good as the water going through it in the sense of organics. If your source water has organics or non-ionized ingredients, the DI treatment won't remove them. The best DI unit is actually a dual unit, one for positive ions, and one for negative ions (using two different types of resins). Most suppliers of DI units don't need to provide humans with such water quality, so you won't get much help from them.

You've done the right thing in asking others for what they might be using. However, remember a lot depends upon the water coming out of your tap. Water treatment can only do so much if the source/tap water is loaded with things that the DI system can't remove (e.g., pesticides, etc.).

I can't help you any further on DI systems, since I have not used one alone. Mine is a water softening unit, ahead of DI, ahead of RO treatment with final polishing done by carbon, for my FOWLR system.