How to slow down flow rate?

I am using seachem denitrator and i need flowrates of 50gallons per hour, which is about 150liters per hour. How to achieve that?

Currently I am using eheim 1260 on a 5ft ohf. That is like 2400 flow rate divided by 4 trays, so about 600 liters per hour per tray. I dont think it is wise to try to fix anything there.

So, how do i get a seperate filter for 150liters per hour flowrate? Even eheim 1046 has like 300 liters per hour. Are there any tricks?

[Arohobs]

a potentially easier option will be to just use Seachem Matrix. its exactly the same thing( Just larger in size) as Seachem denitrator, made for flow rates >50GPH

I already bought the denitrator and denitrator removes nitrate better. I have 0 nitrite but alot of nitrates, like 100 ppm

[Jon-san]

Originally Posted by Kisuke

I already bought the denitrator and denitrator removes nitrate better. I have 0 nitrite but alot of nitrates, like 100 ppm

I think water change removes nitrates a lot faster than Denitrator.

Possible solution #1
If you really need to, just buy a small canister, place it on the floor to pump up to your tank height, sure very slow flowrate. Then again, after awhile, you may find the canister pump will suffer as well.

Possible solution #2 (not sure if this can work, but it's worth a try)
DIY a mineral water bottle, insert in air stone, poke 1 hole at the bottom for water to flow through and several holes at the top for water to flow out. Similar to K1 concept. May work or may not work, but it's cheaper to try. Ugly though.

All things said, I prefer to keep things simple by just doing water change...

Originally Posted by Jon-san

I think water change removes nitrates a lot faster than Denitrator.

Possible solution #1
If you really need to, just buy a small canister, place it on the floor to pump up to your tank height, sure very slow flowrate. Then again, after awhile, you may find the canister pump will suffer as well.

Possible solution #2 (not sure if this can work, but it's worth a try)
DIY a mineral water bottle, insert in air stone, poke 1 hole at the bottom for water to flow through and several holes at the top for water to flow out. Similar to K1 concept. May work or may not work, but it's cheaper to try. Ugly though.

All things said, I prefer to keep things simple by just doing water change...

I am doing water changes but it is not sufficient. Around 20-30% changes every 4 days or so. When I do such frequent water changes, i kinda waste the ocean earth that i keep putting in the tank and i dont think it is any gd for the fish either for it to be too frequent.

I dont think the bottle method will work much though. My tank is 6x2.5x2 ft and the bottles can only be in so many areas.

[issacyeo]

how high is ur nitrates?
i would think the best solution is to go to the root cause:
- is ur bioload too high? too many fishes?

[doyc76]

Originally Posted by Kisuke

I am using seachem denitrator and i need flowrates of 50gallons per hour, which is about 150liters per hour. How to achieve that?

Currently I am using eheim 1260 on a 5ft ohf. That is like 2400 flow rate divided by 4 trays, so about 600 liters per hour per tray. I dont think it is wise to try to fix anything there.

So, how do i get a seperate filter for 150liters per hour flowrate? Even eheim 1046 has like 300 liters per hour. Are there any tricks?

Firstly, 50gph is about 190lph and not 150lph as above unless my calculations are wrong.

Don't know what your OHF stacking is like but wouldn't the flowrate still be closer to 2400lph irrespective of how you're staking them? Assuming the pump is performing at the stated output, then you're still going to be pushing 2,400lph through your OHF. Admittedly of course based on the physical dimensions of the OHF/Sump/canister, the actual flowrate through the compartment(s) would be a little less.

To get a more accurate number i'm thinking you'd need to calculate the volume of your OHF and divide 2,400lph by that. Of course there's probably a proper scientific formula for volumetric flow but that could be too cheem.

I too am grappling with how to keep NO3 at as low a value as possible. Of course water changes are a must but i can't really do 50% twice a week on a consistent basis.

The problem with NO3 is that the bacteria that breaks NO3 down is anaerobic...which is opposite to the aerobic bacteria required for breakdown of NH3 & NO2.

In our tanks, we want high O2 levels which is good for our livestock and BB for NH3 & NO2....but then we need to dissolved O2 levels to plummet for the NO3 bacteria.

I don't have personal experience with OHF's so i might be talking out of my ass here but i don't think effective NO3 breakdown is possible in OHFs. Even in sumps i don't think it is effective.

For NO3 breakdown in between WC, you'd probably need a dedicated denitrator.

I'm still trying to understand how it all works.

Essentially what a denitrator does is it serves as a reaction chamber where the flow is controlled (ie. slow) and there isn't a whole lot of surface area for air-water exchange (ie. to keep dissolved O2 levels as low as possible).

Then there's the whole issue of providing nutrients to the BB that break down NO3. This is where i get fuzzy on the topic.

I bought a Dymax XD-900 Denitrator recently. The maximum capacity listed is for aquariums up to 900 litres. My tank is a little bit more than that but close-ish. It comes with what could be called bio-balls as the reaction media. I replaced that with Seachem's Matrix since that is supposedly designed for NO3 bacteria. The XD-900 design isn't without its flaws but what i'm interested in is whether it works or not.

Theoretically it should...but it didn't really. Talked to the Dymax people (AquaEmpire) and they said that you need to 'feed' the BB. To do that, there is a box of pills (Denitro Plus - 40 pills) & Deniballs. I think the difference is the pills are quick release whilst the Deniballs are slow release. Anyways, i went for the quick release option. Popped in all 40 pills as per instruction and waited. Next evening upon reaching home from work, my tank was cloudy like nobody's business. Immediately tested for NH3 and NO2. Luckily values were still 0. It was a bacteria bloom for sure. Tested NO3 from the output of the denitrator and lo and behold, for the first time ever, 0!

Pills were completely dissolved and i'm guessing it was way too much causing a bacterial bloom. Didn't test tank water NO3 though cos the flow rate of the denitrator isn't enough to turn the tank over in a 24 hour period.

The bacterial bloom cleared up over the next 24 hours but unfortunately, without the source of nutrients, the denitrator also lost its effectiveness. Output was slightly lower than tank NO3 levels but with such a small / slow discharge rate, i need it output to be nil on NO3.

I guess i'm still having teething problems so i can't say that its a system that works reliably.

Just to clarify also, the flow into the denitrator is at its maximum what you could push through an airhose tubing. That's it! So the output needs to be 0 nitrates, otherwise why bother.

Got other issues like a reliable flow rate. I've set up the unit in my sump, drawing water from the second last compartment (which theoretically should be the volume of water with the least dissolved O2)...but found that the internal pump is not strong enough to reliably suck water through the tubing into the denitrator. Instead, i'm now drawing water from the main tank and using the help of gravity...but at the downside is that dissolved O2 would be the highest in the main tank.

Also, no more BB food in the denitrator, so i don't know if it's still working. Will take a reading in the next day or so and report back...but i'm not optimistic. I'm thinking i need to put in some deniballs as a slow release food source...but at the moment, kinda lazy to pull that sucker out from the sump.

Then there's also Sulpher based denitrators. That one i lagi blur.

So in summary...though your intentions are sound, i think it might be a waste of time & effort that should be directed at more frequent WCs. Sadly for me too, i think that could be the brutal truth.

Originally Posted by issacyeo

how high is ur nitrates?
i would think the best solution is to go to the root cause:
- is ur bioload too high? too many fishes?

I have 2 big arowanas, one 5 year old and the other about 2.5 years old, and one 8-9 inch pleco. I have a bunch of floating plants and i use a 2 foot light directly on them as well, to reduce nitrates.
I am cutting down on feeding already. Nitrite and ammonia is 0.

Originally Posted by doyc76

Firstly, 50gph is about 190lph and not 150lph as above unless my calculations are wrong.

Don't know what your OHF stacking is like but wouldn't the flowrate still be closer to 2400lph irrespective of how you're staking them? Assuming the pump is performing at the stated output, then you're still going to be pushing 2,400lph through your OHF. Admittedly of course based on the physical dimensions of the OHF/Sump/canister, the actual flowrate through the compartment(s) would be a little less.

To get a more accurate number i'm thinking you'd need to calculate the volume of your OHF and divide 2,400lph by that. Of course there's probably a proper scientific formula for volumetric flow but that could be too cheem.

I too am grappling with how to keep NO3 at as low a value as possible. Of course water changes are a must but i can't really do 50% twice a week on a consistent basis.

The problem with NO3 is that the bacteria that breaks NO3 down is anaerobic...which is opposite to the aerobic bacteria required for breakdown of NH3 & NO2.

In our tanks, we want high O2 levels which is good for our livestock and BB for NH3 & NO2....but then we need to dissolved O2 levels to plummet for the NO3 bacteria.

I don't have personal experience with OHF's so i might be talking out of my ass here but i don't think effective NO3 breakdown is possible in OHFs. Even in sumps i don't think it is effective.

For NO3 breakdown in between WC, you'd probably need a dedicated denitrator.

I'm still trying to understand how it all works.

Essentially what a denitrator does is it serves as a reaction chamber where the flow is controlled (ie. slow) and there isn't a whole lot of surface area for air-water exchange (ie. to keep dissolved O2 levels as low as possible).

Then there's the whole issue of providing nutrients to the BB that break down NO3. This is where i get fuzzy on the topic.

I bought a Dymax XD-900 Denitrator recently. The maximum capacity listed is for aquariums up to 900 litres. My tank is a little bit more than that but close-ish. It comes with what could be called bio-balls as the reaction media. I replaced that with Seachem's Matrix since that is supposedly designed for NO3 bacteria. The XD-900 design isn't without its flaws but what i'm interested in is whether it works or not.

Theoretically it should...but it didn't really. Talked to the Dymax people (AquaEmpire) and they said that you need to 'feed' the BB. To do that, there is a box of pills (Denitro Plus - 40 pills) & Deniballs. I think the difference is the pills are quick release whilst the Deniballs are slow release. Anyways, i went for the quick release option. Popped in all 40 pills as per instruction and waited. Next evening upon reaching home from work, my tank was cloudy like nobody's business. Immediately tested for NH3 and NO2. Luckily values were still 0. It was a bacteria bloom for sure. Tested NO3 from the output of the denitrator and lo and behold, for the first time ever, 0!

Pills were completely dissolved and i'm guessing it was way too much causing a bacterial bloom. Didn't test tank water NO3 though cos the flow rate of the denitrator isn't enough to turn the tank over in a 24 hour period.

The bacterial bloom cleared up over the next 24 hours but unfortunately, without the source of nutrients, the denitrator also lost its effectiveness. Output was slightly lower than tank NO3 levels but with such a small / slow discharge rate, i need it output to be nil on NO3.

I guess i'm still having teething problems so i can't say that its a system that works reliably.

Just to clarify also, the flow into the denitrator is at its maximum what you could push through an airhose tubing. That's it! So the output needs to be 0 nitrates, otherwise why bother.

Got other issues like a reliable flow rate. I've set up the unit in my sump, drawing water from the second last compartment (which theoretically should be the volume of water with the least dissolved O2)...but found that the internal pump is not strong enough to reliably suck water through the tubing into the denitrator. Instead, i'm now drawing water from the main tank and using the help of gravity...but at the downside is that dissolved O2 would be the highest in the main tank.

Also, no more BB food in the denitrator, so i don't know if it's still working. Will take a reading in the next day or so and report back...but i'm not optimistic. I'm thinking i need to put in some deniballs as a slow release food source...but at the moment, kinda lazy to pull that sucker out from the sump.

Then there's also Sulpher based denitrators. That one i lagi blur.

So in summary...though your intentions are sound, i think it might be a waste of time & effort that should be directed at more frequent WCs. Sadly for me too, i think that could be the brutal truth.

I have read cases where they have used the denitrate effectively, same with denitrator. I am nt gonna use pills or anything. I just wanna use a slower flow rate so my denitrate media is working at its best, then i will see how. I already bought the denitrate lol.

Originally Posted by issacyeo

how high is ur nitrates?
i would think the best solution is to go to the root cause:
- is ur bioload too high? too many fishes?

Forgot to say, nitrate is at about 100ppm.