Overdoing Water Changes

[Radek Z]

Can I overdo water changes?

I had (well still have) some algae problems (staghorn mainly) and I concluded that I must have been overfeeding because my phosphates were way too high (3-4 mg/l). Bacause I did not like to start ripping the things out of the tank and bleaching the decor and plants I thought I would try to starve the staghorn slowly (in parallel I am still picking the algae by hand as much as I can).

So I have started frequent water changes - this is 240l tank, planted and has probably 20in of fish. I have been doing 50-60l changes every three days - as fast as I can produce the water with the small RO I use (my tap water is what I call liquid calcium so I have to RO it to get soft water).

The PO4 is coming down slowly - last night 0.5 and I am wondering about next steps. The concern is that the tank did not show any nitrates for last the-four weeks, I kept plant fertilizing down because I read somewhere Iron might be contributing to the staghorn's happiness. The test for Fe shows zip.

If I go for once a week 60l change I suspect the nitrates will still show 0 before the water change. Can I overdo the water changes?

[PumaWard]

You could probably do that water changing schedule every day if you wanted.

Are you mixing your RO with your tap? If not, you probably should. Calcium, magnesium, and iron are all vital to the health of your plants, without those they will not look their best and won't grow much. Growing plants take a lot of nutrients away from the algae and aids in your plants well being. This, in a sense, starves the algae without starving your plants.

If you can get a a few large bunches of hornwart or other fast growing plants and let them float in your tank or plant them, they will quickly start removing nutrients vital to the algae. Then, if you don't like them, you can pull them out.

BTW, is staghorn algae a type of hair or brush algae?

[Radek Z]

I am adding a powder supplement to the RO to reminarelize it.

Staghonr looks like brush growing out of pretty much anything. It's dark gray when underwater , when dried for few days it turn blueish. It get about 2 in tall.

[PumaWard]

Hmm, maybe some florida flag fish can help out? They eat black hair, so they might eat that as well.

[TKOS]

I was having aproblem with black hair algae and started doing daily water changes. It slowly got things under control and without any harm to plants or fish.

The good thing about lots of water changes is that it helps keep the water quality very stabil. My water starts to get quite acidic if left too long do to my low hardness. By doing more water changes I keep it closer to my tap water. That way if there is a major problem (such as a little kid dumping a bottle of food into the tank) then I can do huge water changes without any pH swings.

[Radek Z]

This is it how my staghorn looks like...

http://www.aquaticscape.com/articles/algae/staghorn_tb.jpg