15g water change for a 26g tank . . . too aggressive?

[knutcracker]

need to drastically lower nitrate (now at 30ppm). will my torch, hammer, leathers, zoos, trumpet, mushrooms, purple tang, jawfish, 6-line wrasse survive? I have 40-50 lbs of LR, so I probably have about 25g of water in the tank. Thanks

[Reefland]

30ppm isn't so high that you need to change 60% of your water. You should do a good size change, perhaps 8 gallons or so and try to identify the cause of the increase.

[knutcracker]

thanks for the reply, scott.

i posted earlier that I did a 10g water change and still didn't put a dent in the nitrates, that's why i am thinking about doing a 15g change. but i suppose it is possible that nitrate level didn't drop because I didn't service my canister Eheim before the 10g change, so all the junk gets back in the tank.

what do u recommend? right now I have 15g of RO/DI water mixed. I have no time to run constantly to the fishstore to buy water, so i would like to solve the problem (bring level down to less than 10ppm) within these 15g of new water. I figure if I only do 10g, and then do the 5, it would be a waste effort, but if I do a 15g, I just might be able to solve the problem.

what do you think?

[Reefland]

If your tank is established then you can go ahead and do the 15 gallon since you have the water already made up. With an established tank and quality liverock I think you'll be fine. However your nitrates are on the increase for some reason and that needs to be fixed or it's only going to continue.

[knutcracker]

i feel embarrassed saying this . . . but it's probably because I haven't done a water change (before the 10g one 2 days ago) in 6 weeks . . . (flame suit on)

[knutcracker]

that's why I did a 10g change, serviced my canister Eheim and my CPR bakpak, and will now do the 15g change. that should do it.

[James]

As I said in your other post, Get rid of the canister filter. They are notorious for harboring nitrates. If you don't believe me, do your water change and unhook the canister filter for one week, then test your water.


Quote'
"i feel embarrassed saying this . . . but it's probably because I haven't done a water change (before the 10g one 2 days ago) in 6 weeks . . . (flame suit on)"

I hope you didn't go 6 weeks without cleaning the canister filter.. ...If you decide to keep it, you really need to service it every 2-3 days to keep food and waste product from building up in there (the probable cause of your nitrates).

[zhenya]

I'd have to agree with James on your canister filter situation and that it is probably the cause of your NO3 build up. I think making a small sump and hang on overflow would solve your problem. Also, get rid of all the sponges and other media that may accumulate particulate matter and concentrate on the cleaning everything. You can do this during the water changes. Having sump will encrease your overall volume of water and give you a place that you can maintain clean and free of detritus by cleaning regularly( not fooling around with different media bags).

I also think that if you do smaller weekly exchanges it will be better for your livestock.

[MarinePig]

I agree. Get rid of the cannister filter. Get a sump (preferably not a wet/dry but you can adapt those to work).