Frequent Asked Questions | D-D The Aquarium Solution


I am wondering if you could tell me what size the nut fitting is on
these chillers? Is it a 1 1/2" BSP fitting or 1 1/4" BSP fitting, or
something else entirely?



I am really hoping you can help me with an issue I have regarding the lighting set up I want to put together. I have
A 50 inch by 24 inch tank and I plan to create an LED/T5 hybrid system. It would comprise of two AI Hydra 52HD Led
Lights and two razor 39W T5s either side of the LEDs (see attached pdf for diagram), possibly staggered as they are a
bit shorter than the tank length.

My issue is how to hang these lights together in a way that looks ok and is practical (ie. Not too difficult to get into tank for maintenance).
I notice that you offer a range of hanging solutions for the hydra lights and also a hanging system for the Razor lights. Is there
Some way that I could use one of these hanging options to attach the LEDs and T5s?

Any help or advice would be greatly appreciated

Thanks and kind regards


I am considering a Deltec SC protein skimmer for my 600l Tridacna 160 which is 
reasonably heavily stocked. I have a good size sump 4x1x11/2 so space isn't a 
huge issue.

I would say the tank is pretty well stocked (matured) with around 100kg of 
live rock assorted fish and predominantly soft corals at this time.

I feed quite heavily with Nori and Flake and a home made mix of various 
frozen. Quite small amounts which is diluted in RO and squirted in as a 
solution to allow maximum distribution.

The current protein skimmer I run is a old convered Red Sea Marine Berlin Classic 
which has the kent mod and an Eheim pump. It actually works pretty well so 
would need to justify the improvement would be worth while.

Which Deltec SC protein skimmer would be most suitable I know the Deltec MCE600 (400l/h) 
works very well but have no experience with the insump designs. There seems 
to be a lot of conflicting information on over skimming would the over large 
model be better or by heavy stocking figures have you covered that issue 

How easy are the spares to get such as replacement pump and impellor as I 
like the idea of the DC pump but trying to work out if its a worthwhile 

Thanks for any advice

Good afternoon

I have just purchased your 20w uv steriliser for my 850l tank. I have read to 
kill whitespot I will need a flow rate of 416lph. I have got the output on my 
d-d phosphate reactor running at approx 120lph. would there be a problem in 
me running at this rate??????

many thanks

HI Could you please give me your opinion what would be the optimum settings 
for growth,with my 2 hydra 52 lights,also the best height. Tank is reefer 
Thanks for your help
Regards XXXX

Hi can you help have sett prime up and I am trying to set the Luna cycle
In the easy setup I have Luna start time at 8:30pm to 11;30pm have set deep 
blue slider to 5 percent but the blue light is on all night long
How do I get the light to come on only with in the Luna period please do you 
go to the graph and set the light to come on using the green bar and if so 
how dose it follow the moons cycle

Thanks for your help and I must say a great light


Dear Wyn

Much depends on the stock you wish too keep and the mount height off the water.

For a system with soft coral,LPS and a few SPS that are situated in high light areas 2 x 26 will be fine at around 10-12” off of the water surface.

For an SPS biased system I would suggest 3 x 26 or 2 x 52 mounted at between 8-12” off of the water surface. (bottom of the light to the water surface)

The new brackets will be with us shortly, powder coating is under way, they will then need to be packed and sent out so we are hoping to get into store this coming week.

Best regards Tony

Dear Tony
two questions:
1)out of 130 liters how much max biopellets can I add?
2)can I use Rowaphos with biopellets?
Thank you

How many cups would generally be used of H2Ocean Pro per gallon for a

Directions say to use 1 pound per 3 gallons and I have no way to weigh it.

Thank you!!

I have a D&D DC-750 cooler that I wish to store during the cool months.  The instructions say store in a dry and safe place but doesn’t mention temperature.
Is it OK to store in a dry brick-built garage?

Good morning
my name is Davide and two months using your biopellets in my innovative marine Aquarium by 150 l.
I wanted to know if I can add some food for corals sps or lps or phytoplankton.
And how can I use, I'm now at most biopellets 100 ml two fish and some sps and lps.
nitrates 0.05
phosphates 0.03
Thank you

I've got a skinny 9 gallon nano tank with about 7 gallons of water. I started using 7 ml of Rowaphos a few weeks ago because of a bad green hair algae outbreak. It's in a bag right on top of the intake to a pump in the intank sump so it's getting good flow. Not fluidized of course though. It hasn't really helped with the gha yet. I suspect my rocks are leaching phosphate. My Red Sea phosphate test kit has always read about .02 but I've heard they aren't that accurate.

But here's the real problem. My alkalinity dropped from high 9s to low 8s. I understand that this is typical. I've been trying to compensate by adding more buffer. I use the RedSea separate A,B,and C liquids for dosing. But the B buffer(even before the increase) seems to just precipitate on the glass and everything nearby including some macroalgae. Even a drop turns white and breaks into little bubbles until it finally dissolves.

A local guy said to do a massive 75% water change discounting the Rowaphos, but these Rowaphos alkalinity effects seem pretty well discussed on the web. Should I keep upping the dosage of part B ? I was using 7-8ml per day before the Rowaphos to maintain high 9s and now I've been using 9-10 and still get the low 8s alkalinity. I'm up to 10-11ml a day now but is that going to just end up on my glass?  My esv water I purchase premixed is naturally only at high 8s but I've always been able to dose up the water to the high 9s with the B additive.  What would you suggest. Thanks, Phil.

Hi can you give me some advice please.
I have a Kent Bio Reef which is similar to your nano tank
i wish to upgrade the lights and i am looking at your AI prime
if i was to remove the lid have a peace of acrylic or glass cut to fit over 
the top with a square hole cut out in the centre and use your AI bracket on 
the rear of the back filter section would the light reach far enough over the 
tank or would i need to mount it on the tank rear wall . Would one light be 
sufficient and what type of corals would it support
i know it is a lot to answer butmy LFS just want to make a sale

many Thanks Paul


I was just wondering how long it normally takes before algae grows over the 
i have just put a load of frags in my tank, and unfortunately it looks like a 
load of bubble gum is everywhere!



Dear Stuart,Rob,
we have a lot of question in regard the refractometer from your Company.
If we assume that the refractive index of Seawater is 1.3394 at 35 PPT Equivalent Seawater Salinity a calibration Solution of Sodium Chloride with 3.65 g in 96.35g Ro Water must show a salinity on your Refractometer of 35 PPT, however our readings are 33PPT.
So please help us to understand if the readings are above or under the real Seawater Salinity.
We have Tested the Grotech Salinity Refractometer as well as the Mircrobe Lift and Red Sea and all of them have different readings in PPT with the same solution and proper calibration with RO Water.
Can you please explain us what we can tell our dealer and supplier if those question are coming up, or did you have a 35PPT solution in order to Calibrate the Refractometer properly
Thank you
Awaiting your response