Would PH and nitrate cause an algea bloom??

[wan 2 B reef'in]

My tank is starting to get some algea in it not the favored coraline, which for some reason doesn't want to grow. It's also not the dark green I remember seeing from when there was a hair algea problem. It is light green, as well as red (macro???). Also it's growing very short not long like the hair... I'm sure it could get long though.

I tested the water and the only things I wonder about is the ph 7.8, and nitrate which is somewhere in the 20-40ppm range.

My first thought was phosphate, but my reactor has that in check at 0ppm. Nitrite is 0, Amonia 0, Calcium I'll admit is a little high around 620 but that is due to a sudgestion from a friend who advised me to use an ionic calcium vs. kent calcium (due to another issue).

I was told it was probably the water I use, tap no RO unit yet
yes I know I should get one, and will soon.

Anyway back to the original question..... can ph and trate cause algea??

thanks for any and all info.

[bertoni]

The nitrate is alga food, so its presence indicates plenty of food for growth. pH generally isn't as critical for algae, but that pH is a bit low, particularly if that measurement was taken in the afternoon. These articles might help:

http://reefkeeping.com/issues/2004-09/rhf/index.htm
http://www.advancedaquarist.com/issu...t2003/chem.htm

[wan 2 B reef'in]

thanks I'll check it out

[bertoni]

You're welcome!

[knumbnutz]

Red algae is probably cyanobacteria. It usually is a result of 1) poor lighting, 2) poor water flow, 3)excess nutrients. It could be any one of these things or a combination of the above issues. The other thing 7.8 pH is a low reading, keep in mind that pH and Alk are directly tied to one another. So if your alk is in range I would venture a guess that you have excess CO2 in the system and that is keeping the pH low, best fix is to aerate the water to deplete the excess CO2 and/or put a fan on the tank to increase circulation and improve gas exchange. Once you get your pH and Alk in range you can start to battle the algae problem, but its sounds like you may have excess nutrients in the tank. Maybe cut back on feeding until you can get the system in balance. Remember to be patient and make changes slowly, you do not want to create new problems. Hope this helps!!

[knumbnutz]

Final thought, you can spot check and see if CO2 is an issue by taking and water sample test the pH, then aerate the sample water and retest the pH. If the pH comes into range you have excess CO2 in the system.

[wan 2 B reef'in]

I did cut back a little on the feeding, thanks for the tip on the ph test. I'm going to give it a try.

[Percula9]

Calcium levels are high due to low alkalinity, If you are using a protein skimmer CO2 shouldn't be a big issue. Nitrate levels can cause algael blooms.Don't use tap water, use R/O water from your local fish store. Always PH correct your top off water with buffer. Do more frequent water changes. People rely to much on supplements. High alkalinity will dicourage cyanobacteria from growing. If it becomes a problem use red slime remover it works very good. Without carbonate hardness the calcium has nothing to attach to, this is why your cacium levels are high.

[Billybeau1]

I do not recommend buffering top off water. There is absolutely no reason to. All you will do is drive your alkalinity up. The pH of top off water is insignificant.

Red slime remover is a short term fix and does not solve the problem. The algae will be back if you do not find the source and correct it.

Calcium is not your issue either. It will fall since you stopped adding supplements.

I still think you have PO4. You may not be showing it, but I think its there.

You could run some GFO in a canister filter to soak up what little you have. That should stop the algae.

[bertoni]

I agree that the pH of topoff water is irrelevant since it has no buffering. Also, the pH of RO and RO-DI water can't be measured accurately with our hobbyist kits in any case.

High calcium levels are not due to low alkalinity. They are caused by too much calcium being added.

[knumbnutz]

I agree with Billybeau PO4 and silicates from the tap water are going to be the source of the algae bloom. The PO4 may not show up on the tests because it is being used up by the algae blooms.

Use RO/DI topoff and you may want to look into Algone the reduce the nitrates and free your system of nutriets the algae like. I have been using Algone for a while now and it does as advertised.

Just a thought shouldn't RO/DI water have a pH around 7.0? The idea being you've removed anything that would affect the pH.

[bertoni]

The pH of RO-DI water can vary rapidly. Absorption of CO2 gas, for example, will lower the pH via the formation of carbonic acid.

[wan 2 B reef'in]

Thanks all, for all the info. I'll keep you posted on what happens next