75 gallon tank 20 months old

[Galvan]

I have a 75 gallon tank with 90lbs of LR about a 3.5 inch sand base with sump and skimmer. 8 animals and 3 corals. I'm working on getting my Nitrate down it is running abot 80-100ppm and has always been this way, i just have not been able to get in the 0-10 range. Question is can I do 10 gallon water changes every week in order to try and get this down to about 5ppm. I'm afraid if i do too many water changes this may some how affect my fish. Is too many water changes bad..

galvan

 

[Anonymous]

No, too many waterchanges will not hurt your fish, provided that you make sure that your new water about matches the salinity and temp of your tank. However, 10 gal on a 75 is not a huuuuuge waterchange. You could do bigger ones initially to really get your numbers down.

Adjust your skimmer so it is skimming wet and pulling more out. Also take a powerhead and periodically blow out all the nooks and crannies in your rock so that there is not a build up of detritus. When you do your water change, take the siphon hose and suck up and little piles of detritus you find on the rock or sand.

 

[Anonymous]

Also, that just does not look to me like a tank that has 100ppm nitrate. Not that looks mean much, but it looks pretty clean and you only have a couple fish. (That I can see)

Are you sure your test kit is right?

 

[dadstank]

"Adjust your skimmer so it is skimming wet and pulling more out"

what do you mean skimming wet?

 

[Anonymous]

Galvan

Getting another test kit like LauraD suggested is a good idea. If your water does truly test that high, here's a good article to read that will give you an idea just how much water you'll have to change to affect those values:

http://www.reefs.org/library/article/t_ ... ll_wc.html

It's a good read, but whats really applicable here is this graph:

10 gallons a week (less than 7% of total volume) won't make a dent in numbers that high. You'll have to not only change a lot more water than 7%, you should analyze where those high levels are coming from. Overfeeding maybe or inadequate skimming or even your source water are good places to start looking.

As far as water changes effecting fish, as long as you let the make up water age 24 hours with good aeriation and match the temperature, pH and SG of your main tank before you change out the water the fish won't be bothered at all.