Keeping Nitrates DOWN in Predator tank! Help!

[Kenneth's Tropical Fish]

Hello everyone,

I have a question that I might have already figured out but want others input as well. I have a predator tank with sharks, rays, puffers, and a eel. I've been battling with Nitrates for a while and the best I've managed to lower them to is 20ppm with 70% water changes every 4 days and I'm tired of wasting so much salt. I'm not looking for "nutrient Control" chemical filtration because that doesn't help lower nitrates only keep it from getting worst. I need something that will remove "Nitrate" quite literally. I have a skimmer but I'm under the impression that it only removes nutrients that have broken down and it doesn't "Skim" Nitrates directly. I'm trying to minimize or remove water changes all together if possible. I'm under the impression Chaeto or macroalgae will remove the nitrate directly but I wanna know if that's true in its entirety. Is anyone running a refug with chaeto or other macroalgae? Currently my Nitrates are 64ppm and the fish all seem fine but I just don't want it to climb to deadly levels. I know there are alot of products on the market that help with breaking down nutrients "before" they turn to ammonia then nitrites and finally nitrates. I'm looking for the real deal is there anything out there that strips nitrates from the water and lower them without water changes? I don't care if I have to change out media every so often I just don't wanna do as many water changes this tank is a 300 gal and is costing me a fortune. Many thanks you guys

 

[BlazinNano]

If you are able to run a refuge I would. It may not bring it to 0 but it will help. With your levels the macro algae will have plenty to feed off of.

 

[paul01609]

Could also look in to carbon dosing

 

[Goodair]

I got some macros and corals, nitrates have always been low and but phosphates are always the one that is high. Chaeto with a skimmer and filter socks should be sufficient, (keep in mind all tanks will be different) but it should be enough. Also make sure its set up properly to get a more optimal performance.
Since your tank would have a pretty high bioload, you would need more macro. You won't be able to avoid water changes, but you can definitely reduce it from every 4 days to weekly/biweekly since sharks do need pretty good water.

Edit: with your stocking, you can even look into ornamental macros to add some color to a tank, since you don't have tangs or other herbivores that would eat it the day you add them in!

 

[lion king]

Yes chaeto, or macro algae, I like caulerpa. You can add a refuge if you have room, running an effective fuge requires a much slower flow than you will get through your sump, so it has to designed as a fuge or added on. You want at least 10% volume for the macro compared to the tank. Macro algae reactors or an algae scrubber, I find scrubbers a pita. For a 300g you'll need a pretty large reactor or even run duals.

Carbon dosing, nopox or any of the other forms.

Nitrate reactors, they work but can be expensive as the media gets saturated and needs to be replaced, and if not replaced in time will leach nitrates back into the system. Marine pure never worked for me but has the same theory as nitrate reactors, building on anerobic bacteria.

Biopellet reactors, I never had success with these.

My favorite and most successful is a fuge, I also like macro reactors but hate the maintenance. I do successfully use nopox on one tank.

If you are battling algae you can cut down on lighting times, I keep my predator tanks that aren't reefs lite only for viewing hours, 5-6 hours in the evening. Lower light levels help as well.

 

[AlexG]

Before making a recommendation I would like to know more about your system. Can you provide a full stocking list of whats in the tank? Do you have any live rock in the system or just dead rock? What is the filtration system setup on your tank? Do you use filter pads, filter socks? if so how often are they changed? If we can determine the source of the nitrates it will be possible to help reduce their production while also introducing some mitigation methods. I had 80+ppm of nitrates in a fish only tank for years and the solution was to reduce the sources of nitrates along with adding denitrification.

 

[Aqua Man]

Donovan’s nitrate destroyer Might of spelled his name wrong. It’s a diy project he invented. There is a thread on here somewhere!

 

[ThePurple12]

A DIY algae scrubber would be great for your tank. They're extremely effective, really cheap, and won't take nutrients from any plants.

 

[DaddyFish]

Try a large HOB loaded with Matrix. Turn the GPH flow rate almost all the way down to get it below 50 gph. Been my experience that after a 4-6 week period, long enough for anaerobic bacteria to establish, it will knock a large dent in your nitrates.